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2012-10-21xen/bootup: allow read_tscp call for Xen PV guests.Konrad Rzeszutek Wilk
commit cd0608e71e9757f4dae35bcfb4e88f4d1a03a8ab upstream. The hypervisor will trap it. However without this patch, we would crash as the .read_tscp is set to NULL. This patch fixes it and sets it to the native_read_tscp call. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-21xen/bootup: allow {read|write}_cr8 pvops call.Konrad Rzeszutek Wilk
commit 1a7bbda5b1ab0e02622761305a32dc38735b90b2 upstream. We actually do not do anything about it. Just return a default value of zero and if the kernel tries to write anything but 0 we BUG_ON. This fixes the case when an user tries to suspend the machine and it blows up in save_processor_state b/c 'read_cr8' is set to NULL and we get: kernel BUG at /home/konrad/ssd/linux/arch/x86/include/asm/paravirt.h:100! invalid opcode: 0000 [#1] SMP Pid: 2687, comm: init.late Tainted: G O 3.6.0upstream-00002-gac264ac-dirty #4 Bochs Bochs RIP: e030:[<ffffffff814d5f42>] [<ffffffff814d5f42>] save_processor_state+0x212/0x270 .. snip.. Call Trace: [<ffffffff810733bf>] do_suspend_lowlevel+0xf/0xac [<ffffffff8107330c>] ? x86_acpi_suspend_lowlevel+0x10c/0x150 [<ffffffff81342ee2>] acpi_suspend_enter+0x57/0xd5 Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-02xen/boot: Disable NUMA for PV guests.Konrad Rzeszutek Wilk
commit 8d54db795dfb1049d45dc34f0dddbc5347ec5642 upstream. The hypervisor is in charge of allocating the proper "NUMA" memory and dealing with the CPU scheduler to keep them bound to the proper NUMA node. The PV guests (and PVHVM) have no inkling of where they run and do not need to know that right now. In the future we will need to inject NUMA configuration data (if a guest spans two or more NUMA nodes) so that the kernel can make the right choices. But those patches are not yet present. In the meantime, disable the NUMA capability in the PV guest, which also fixes a bootup issue. Andre says: "we see Dom0 crashes due to the kernel detecting the NUMA topology not by ACPI, but directly from the northbridge (CONFIG_AMD_NUMA). This will detect the actual NUMA config of the physical machine, but will crash about the mismatch with Dom0's virtual memory. Variation of the theme: Dom0 sees what it's not supposed to see. This happens with the said config option enabled and on a machine where this scanning is still enabled (K8 and Fam10h, not Bulldozer class) We have this dump then: NUMA: Warning: node ids are out of bound, from=-1 to=-1 distance=10 Scanning NUMA topology in Northbridge 24 Number of physical nodes 4 Node 0 MemBase 0000000000000000 Limit 0000000040000000 Node 1 MemBase 0000000040000000 Limit 0000000138000000 Node 2 MemBase 0000000138000000 Limit 00000001f8000000 Node 3 MemBase 00000001f8000000 Limit 0000000238000000 Initmem setup node 0 0000000000000000-0000000040000000 NODE_DATA [000000003ffd9000 - 000000003fffffff] Initmem setup node 1 0000000040000000-0000000138000000 NODE_DATA [0000000137fd9000 - 0000000137ffffff] Initmem setup node 2 0000000138000000-00000001f8000000 NODE_DATA [00000001f095e000 - 00000001f0984fff] Initmem setup node 3 00000001f8000000-0000000238000000 Cannot find 159744 bytes in node 3 BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff81d220e6>] __alloc_bootmem_node+0x43/0x96 Pid: 0, comm: swapper Not tainted 3.3.6 #1 AMD Dinar/Dinar RIP: e030:[<ffffffff81d220e6>] [<ffffffff81d220e6>] __alloc_bootmem_node+0x43/0x96 .. snip.. [<ffffffff81d23024>] sparse_early_usemaps_alloc_node+0x64/0x178 [<ffffffff81d23348>] sparse_init+0xe4/0x25a [<ffffffff81d16840>] paging_init+0x13/0x22 [<ffffffff81d07fbb>] setup_arch+0x9c6/0xa9b [<ffffffff81683954>] ? printk+0x3c/0x3e [<ffffffff81d01a38>] start_kernel+0xe5/0x468 [<ffffffff81d012cf>] x86_64_start_reservations+0xba/0xc1 [<ffffffff81007153>] ? xen_setup_runstate_info+0x2c/0x36 [<ffffffff81d050ee>] xen_start_kernel+0x565/0x56c " so we just disable NUMA scanning by setting numa_off=1. Reported-and-Tested-by: Andre Przywara <andre.przywara@amd.com> Acked-by: Andre Przywara <andre.przywara@amd.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-26xen: mark local pages as FOREIGN in the m2p_overrideStefano Stabellini
commit b9e0d95c041ca2d7ad297ee37c2e9cfab67a188f upstream. When the frontend and the backend reside on the same domain, even if we add pages to the m2p_override, these pages will never be returned by mfn_to_pfn because the check "get_phys_to_machine(pfn) != mfn" will always fail, so the pfn of the frontend will be returned instead (resulting in a deadlock because the frontend pages are already locked). INFO: task qemu-system-i38:1085 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. qemu-system-i38 D ffff8800cfc137c0 0 1085 1 0x00000000 ffff8800c47ed898 0000000000000282 ffff8800be4596b0 00000000000137c0 ffff8800c47edfd8 ffff8800c47ec010 00000000000137c0 00000000000137c0 ffff8800c47edfd8 00000000000137c0 ffffffff82213020 ffff8800be4596b0 Call Trace: [<ffffffff81101ee0>] ? __lock_page+0x70/0x70 [<ffffffff81a0fdd9>] schedule+0x29/0x70 [<ffffffff81a0fe80>] io_schedule+0x60/0x80 [<ffffffff81101eee>] sleep_on_page+0xe/0x20 [<ffffffff81a0e1ca>] __wait_on_bit_lock+0x5a/0xc0 [<ffffffff81101ed7>] __lock_page+0x67/0x70 [<ffffffff8106f750>] ? autoremove_wake_function+0x40/0x40 [<ffffffff811867e6>] ? bio_add_page+0x36/0x40 [<ffffffff8110b692>] set_page_dirty_lock+0x52/0x60 [<ffffffff81186021>] bio_set_pages_dirty+0x51/0x70 [<ffffffff8118c6b4>] do_blockdev_direct_IO+0xb24/0xeb0 [<ffffffff811e71a0>] ? ext3_get_blocks_handle+0xe00/0xe00 [<ffffffff8118ca95>] __blockdev_direct_IO+0x55/0x60 [<ffffffff811e71a0>] ? ext3_get_blocks_handle+0xe00/0xe00 [<ffffffff811e91c8>] ext3_direct_IO+0xf8/0x390 [<ffffffff811e71a0>] ? ext3_get_blocks_handle+0xe00/0xe00 [<ffffffff81004b60>] ? xen_mc_flush+0xb0/0x1b0 [<ffffffff81104027>] generic_file_aio_read+0x737/0x780 [<ffffffff813bedeb>] ? gnttab_map_refs+0x15b/0x1e0 [<ffffffff811038f0>] ? find_get_pages+0x150/0x150 [<ffffffff8119736c>] aio_rw_vect_retry+0x7c/0x1d0 [<ffffffff811972f0>] ? lookup_ioctx+0x90/0x90 [<ffffffff81198856>] aio_run_iocb+0x66/0x1a0 [<ffffffff811998b8>] do_io_submit+0x708/0xb90 [<ffffffff81199d50>] sys_io_submit+0x10/0x20 [<ffffffff81a18d69>] system_call_fastpath+0x16/0x1b The explanation is in the comment within the code: We need to do this because the pages shared by the frontend (xen-blkfront) can be already locked (lock_page, called by do_read_cache_page); when the userspace backend tries to use them with direct_IO, mfn_to_pfn returns the pfn of the frontend, so do_blockdev_direct_IO is going to try to lock the same pages again resulting in a deadlock. A simplified call graph looks like this: pygrub QEMU ----------------------------------------------- do_read_cache_page io_submit | | lock_page ext3_direct_IO | bio_add_page | lock_page Internally the xen-blkback uses m2p_add_override to swizzle (temporarily) a 'struct page' to have a different MFN (so that it can point to another guest). It also can easily find out whether another pfn corresponding to the mfn exists in the m2p, and can set the FOREIGN bit in the p2m, making sure that mfn_to_pfn returns the pfn of the backend. This allows the backend to perform direct_IO on these pages, but as a side effect prevents the frontend from using get_user_pages_fast on them while they are being shared with the backend. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-22xen/setup: filter APERFMPERF cpuid feature outAndre Przywara
commit 5e626254206a709c6e937f3dda69bf26c7344f6f upstream. Xen PV kernels allow access to the APERF/MPERF registers to read the effective frequency. Access to the MSRs is however redirected to the currently scheduled physical CPU, making consecutive read and compares unreliable. In addition each rdmsr traps into the hypervisor. So to avoid bogus readouts and expensive traps, disable the kernel internal feature flag for APERF/MPERF if running under Xen. This will a) remove the aperfmperf flag from /proc/cpuinfo b) not mislead the power scheduler (arch/x86/kernel/cpu/sched.c) to use the feature to improve scheduling (by default disabled) c) not mislead the cpufreq driver to use the MSRs This does not cover userland programs which access the MSRs via the device file interface, but this will be addressed separately. Signed-off-by: Andre Przywara <andre.przywara@amd.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-21xen/pci: don't use PCI BIOS service for configuration space accessesDavid Vrabel
commit 76a8df7b49168509df02461f83fab117a4a86e08 upstream. The accessing PCI configuration space with the PCI BIOS32 service does not work in PV guests. On systems without MMCONFIG or where the BIOS hasn't marked the MMCONFIG region as reserved in the e820 map, the BIOS service is probed (even though direct access is preferred) and this hangs. Acked-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> [v1: Fixed compile error when CONFIG_PCI is not set] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-21xen/pte: Fix crashes when trying to see non-existent PGD/PMD/PUD/PTEsKonrad Rzeszutek Wilk
commit b7e5ffe5d83fa40d702976d77452004abbe35791 upstream. If I try to do "cat /sys/kernel/debug/kernel_page_tables" I end up with: BUG: unable to handle kernel paging request at ffffc7fffffff000 IP: [<ffffffff8106aa51>] ptdump_show+0x221/0x480 PGD 0 Oops: 0000 [#1] SMP CPU 0 .. snip.. RAX: 0000000000000000 RBX: ffffc00000000fff RCX: 0000000000000000 RDX: 0000800000000000 RSI: 0000000000000000 RDI: ffffc7fffffff000 which is due to the fact we are trying to access a PFN that is not accessible to us. The reason (at least in this case) was that PGD[256] is set to __HYPERVISOR_VIRT_START which was setup (by the hypervisor) to point to a read-only linear map of the MFN->PFN array. During our parsing we would get the MFN (a valid one), try to look it up in the MFN->PFN tree and find it invalid and return ~0 as PFN. Then pte_mfn_to_pfn would happilly feed that in, attach the flags and return it back to the caller. 'ptdump_show' bitshifts it and gets and invalid value that it tries to dereference. Instead of doing all of that, we detect the ~0 case and just return !_PAGE_PRESENT. This bug has been in existence .. at least until 2.6.37 (yikes!) Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07xen/smp: Fix crash when booting with ACPI hotplug CPUs.Konrad Rzeszutek Wilk
commit cf405ae612b0f7e2358db7ff594c0e94846137aa upstream. When we boot on a machine that can hotplug CPUs and we are using 'dom0_max_vcpus=X' on the Xen hypervisor line to clip the amount of CPUs available to the initial domain, we get this: (XEN) Command line: com1=115200,8n1 dom0_mem=8G noreboot dom0_max_vcpus=8 sync_console mce_verbosity=verbose console=com1,vga loglvl=all guest_loglvl=all .. snip.. DMI: Intel Corporation S2600CP/S2600CP, BIOS SE5C600.86B.99.99.x032.072520111118 07/25/2011 .. snip. SMP: Allowing 64 CPUs, 32 hotplug CPUs installing Xen timer for CPU 7 cpu 7 spinlock event irq 361 NMI watchdog: disabled (cpu7): hardware events not enabled Brought up 8 CPUs .. snip.. [acpi processor finds the CPUs are not initialized and starts calling arch_register_cpu, which creates /sys/devices/system/cpu/cpu8/online] CPU 8 got hotplugged CPU 9 got hotplugged CPU 10 got hotplugged .. snip.. initcall 1_acpi_battery_init_async+0x0/0x1b returned 0 after 406 usecs calling erst_init+0x0/0x2bb @ 1 [and the scheduler sticks newly started tasks on the new CPUs, but said CPUs cannot be initialized b/c the hypervisor has limited the amount of vCPUS to 8 - as per the dom0_max_vcpus=8 flag. The spinlock tries to kick the other CPU, but the structure for that is not initialized and we crash.] BUG: unable to handle kernel paging request at fffffffffffffed8 IP: [<ffffffff81035289>] xen_spin_lock+0x29/0x60 PGD 180d067 PUD 180e067 PMD 0 Oops: 0002 [#1] SMP CPU 7 Modules linked in: Pid: 1, comm: swapper/0 Not tainted 3.4.0-rc2upstream-00001-gf5154e8 #1 Intel Corporation S2600CP/S2600CP RIP: e030:[<ffffffff81035289>] [<ffffffff81035289>] xen_spin_lock+0x29/0x60 RSP: e02b:ffff8801fb9b3a70 EFLAGS: 00010282 With this patch, we cap the amount of vCPUS that the initial domain can run, to exactly what dom0_max_vcpus=X has specified. In the future, if there is a hypercall that will allow a running domain to expand past its initial set of vCPUS, this patch should be re-evaluated. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07xen: correctly check for pending events when restoring irq flagsDavid Vrabel
commit 7eb7ce4d2e8991aff4ecb71a81949a907ca755ac upstream. In xen_restore_fl_direct(), xen_force_evtchn_callback() was being called even if no events were pending. This resulted in (depending on workload) about a 100 times as many xen_version hypercalls as necessary. Fix this by correcting the sense of the conditional jump. This seems to give a significant performance benefit for some workloads. There is some subtle tricksy "..since the check here is trying to check both pending and masked in a single cmpw, but I think this is correct. It will call check_events now only when the combined mask+pending word is 0x0001 (aka unmasked, pending)." (Ian) Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2011-12-21xen: only limit memory map to maximum reservation for domain 0.Ian Campbell
commit d3db728125c4470a2d061ac10fa7395e18237263 upstream. d312ae878b6a "xen: use maximum reservation to limit amount of usable RAM" clamped the total amount of RAM to the current maximum reservation. This is correct for dom0 but is not correct for guest domains. In order to boot a guest "pre-ballooned" (e.g. with memory=1G but maxmem=2G) in order to allow for future memory expansion the guest must derive max_pfn from the e820 provided by the toolstack and not the current maximum reservation (which can reflect only the current maximum, not the guest lifetime max). The existing algorithm already behaves this correctly if we do not artificially limit the maximum number of pages for the guest case. For a guest booted with maxmem=512, memory=128 this results in: [ 0.000000] BIOS-provided physical RAM map: [ 0.000000] Xen: 0000000000000000 - 00000000000a0000 (usable) [ 0.000000] Xen: 00000000000a0000 - 0000000000100000 (reserved) -[ 0.000000] Xen: 0000000000100000 - 0000000008100000 (usable) -[ 0.000000] Xen: 0000000008100000 - 0000000020800000 (unusable) +[ 0.000000] Xen: 0000000000100000 - 0000000020800000 (usable) ... [ 0.000000] NX (Execute Disable) protection: active [ 0.000000] DMI not present or invalid. [ 0.000000] e820 update range: 0000000000000000 - 0000000000010000 (usable) ==> (reserved) [ 0.000000] e820 remove range: 00000000000a0000 - 0000000000100000 (usable) -[ 0.000000] last_pfn = 0x8100 max_arch_pfn = 0x1000000 +[ 0.000000] last_pfn = 0x20800 max_arch_pfn = 0x1000000 [ 0.000000] initial memory mapped : 0 - 027ff000 [ 0.000000] Base memory trampoline at [c009f000] 9f000 size 4096 -[ 0.000000] init_memory_mapping: 0000000000000000-0000000008100000 -[ 0.000000] 0000000000 - 0008100000 page 4k -[ 0.000000] kernel direct mapping tables up to 8100000 @ 27bb000-27ff000 +[ 0.000000] init_memory_mapping: 0000000000000000-0000000020800000 +[ 0.000000] 0000000000 - 0020800000 page 4k +[ 0.000000] kernel direct mapping tables up to 20800000 @ 26f8000-27ff000 [ 0.000000] xen: setting RW the range 27e8000 - 27ff000 [ 0.000000] 0MB HIGHMEM available. -[ 0.000000] 129MB LOWMEM available. -[ 0.000000] mapped low ram: 0 - 08100000 -[ 0.000000] low ram: 0 - 08100000 +[ 0.000000] 520MB LOWMEM available. +[ 0.000000] mapped low ram: 0 - 20800000 +[ 0.000000] low ram: 0 - 20800000 With this change "xl mem-set <domain> 512M" will successfully increase the guest RAM (by reducing the balloon). There is no change for dom0. Reported-and-Tested-by: George Shuklin <george.shuklin@gmail.com> Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-11-21xen:pvhvm: enable PVHVM VCPU placement when using more than 32 CPUs.Zhenzhong Duan
commit 90d4f5534d14815bd94c10e8ceccc57287657ecc upstream. PVHVM running with more than 32 vcpus and pv_irq/pv_time enabled need VCPU placement to work, or else it will softlockup. Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-10-03xen/e820: if there is no dom0_mem=, don't tweak extra_pages.David Vrabel
commit e3b73c4a25e9a5705b4ef28b91676caf01f9bc9f upstream. The patch "xen: use maximum reservation to limit amount of usable RAM" (d312ae878b6aed3912e1acaaf5d0b2a9d08a4f11) breaks machines that do not use 'dom0_mem=' argument with: reserve RAM buffer: 000000133f2e2000 - 000000133fffffff (XEN) mm.c:4976:d0 Global bit is set to kernel page fffff8117e (XEN) domain_crash_sync called from entry.S (XEN) Domain 0 (vcpu#0) crashed on cpu#0: ... The reason being that the last E820 entry is created using the 'extra_pages' (which is based on how many pages have been freed). The mentioned git commit sets the initial value of 'extra_pages' using a hypercall which returns the number of pages (if dom0_mem has been used) or -1 otherwise. If the later we return with MAX_DOMAIN_PAGES as basis for calculation: return min(max_pages, MAX_DOMAIN_PAGES); and use it: extra_limit = xen_get_max_pages(); if (extra_limit >= max_pfn) extra_pages = extra_limit - max_pfn; else extra_pages = 0; which means we end up with extra_pages = 128GB in PFNs (33554432) - 8GB in PFNs (2097152, on this specific box, can be larger or smaller), and then we add that value to the E820 making it: Xen: 00000000ff000000 - 0000000100000000 (reserved) Xen: 0000000100000000 - 000000133f2e2000 (usable) which is clearly wrong. It should look as so: Xen: 00000000ff000000 - 0000000100000000 (reserved) Xen: 0000000100000000 - 000000027fbda000 (usable) Naturally this problem does not present itself if dom0_mem=max:X is used. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-10-03xen: use maximum reservation to limit amount of usable RAMDavid Vrabel
commit d312ae878b6aed3912e1acaaf5d0b2a9d08a4f11 upstream. Use the domain's maximum reservation to limit the amount of extra RAM for the memory balloon. This reduces the size of the pages tables and the amount of reserved low memory (which defaults to about 1/32 of the total RAM). On a system with 8 GiB of RAM with the domain limited to 1 GiB the kernel reports: Before: Memory: 627792k/4472000k available After: Memory: 549740k/11132224k available A increase of about 76 MiB (~1.5% of the unused 7 GiB). The reserved low memory is also reduced from 253 MiB to 32 MiB. The total additional usable RAM is 329 MiB. For dom0, this requires at patch to Xen ('x86: use 'dom0_mem' to limit the number of pages for dom0') (c/s 23790) Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-10-03xen/smp: Warn user why they keel over - nosmp or noapic and what to use instead.Konrad Rzeszutek Wilk
commit ed467e69f16e6b480e2face7bc5963834d025f91 upstream. We have hit a couple of customer bugs where they would like to use those parameters to run an UP kernel - but both of those options turn of important sources of interrupt information so we end up not being able to boot. The correct way is to pass in 'dom0_max_vcpus=1' on the Xen hypervisor line and the kernel will patch itself to be a UP kernel. Fixes bug: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=637308 Acked-by: Ian Campbell <Ian.Campbell@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-10-03xen: x86_32: do not enable iterrupts when returning from exception in ↵Igor Mammedov
interrupt context commit d198d499148a0c64a41b3aba9e7dd43772832b91 upstream. If vmalloc page_fault happens inside of interrupt handler with interrupts disabled then on exit path from exception handler when there is no pending interrupts, the following code (arch/x86/xen/xen-asm_32.S:112): cmpw $0x0001, XEN_vcpu_info_pending(%eax) sete XEN_vcpu_info_mask(%eax) will enable interrupts even if they has been previously disabled according to eflags from the bounce frame (arch/x86/xen/xen-asm_32.S:99) testb $X86_EFLAGS_IF>>8, 8+1+ESP_OFFSET(%esp) setz XEN_vcpu_info_mask(%eax) Solution is in setting XEN_vcpu_info_mask only when it should be set according to cmpw $0x0001, XEN_vcpu_info_pending(%eax) but not clearing it if there isn't any pending events. Reproducer for bug is attached to RHBZ 707552 Signed-off-by: Igor Mammedov <imammedo@redhat.com> Acked-by: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-08-29xen: Do not enable PV IPIs when vector callback not presentStefano Stabellini
commit 3c05c4bed4ccce3f22f6d7899b308faae24ad198 upstream. Fix regression for HVM case on older (<4.1.1) hypervisors caused by commit 99bbb3a84a99cd04ab16b998b20f01a72cfa9f4f Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Date: Thu Dec 2 17:55:10 2010 +0000 xen: PV on HVM: support PV spinlocks and IPIs This change replaced the SMP operations with event based handlers without taking into account that this only works when the hypervisor supports callback vectors. This causes unexplainable hangs early on boot for HVM guests with more than one CPU. BugLink: http://bugs.launchpad.net/bugs/791850 Signed-off-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Tested-and-Reported-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-08-29xen/x86: replace order-based range checking of M2P table by linear oneJan Beulich
commit ccbcdf7cf1b5f6c6db30d84095b9c6c53043af55 upstream. The order-based approach is not only less efficient (requiring a shift and a compare, typical generated code looking like this mov eax, [machine_to_phys_order] mov ecx, eax shr ebx, cl test ebx, ebx jnz ... whereas a direct check requires just a compare, like in cmp ebx, [machine_to_phys_nr] jae ... ), but also slightly dangerous in the 32-on-64 case - the element address calculation can wrap if the next power of two boundary is sufficiently far away from the actual upper limit of the table, and hence can result in user space addresses being accessed (with it being unknown what may actually be mapped there). Additionally, the elimination of the mistaken use of fls() here (should have been __fls()) fixes a latent issue on x86-64 that would trigger if the code was run on a system with memory extending beyond the 44-bit boundary. Signed-off-by: Jan Beulich <jbeulich@novell.com> [v1: Based on Jeremy's feedback] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-08-15xen: allow enable use of VGA console on dom0Jeremy Fitzhardinge
commit c2419b4a4727f67af2fc2cd68b0d878b75e781bb upstream. Get the information about the VGA console hardware from Xen, and put it into the form the bootloader normally generates, so that the rest of the kernel can deal with VGA as usual. [ Impact: make VGA console work in dom0 ] Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> [v1: Rebased on 2.6.39] [v2: Removed incorrect comments and fixed compile warnings] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-06-30xen/mmu: Fix for linker errors when CONFIG_SMP is not defined.Konrad Rzeszutek Wilk
Simple enough - we use an extern defined symbol which is not defined when CONFIG_SMP is not defined. This fixes the linker dying. CC: stable@kernel.org Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-06-16xen/setup: Fix for incorrect xen_extra_mem_start.Konrad Rzeszutek Wilk
The earlier attempts (24bdb0b62cc82120924762ae6bc85afc8c3f2b26) at fixing this problem caused other problems to surface (PV guests with no PCI passthrough would have SWIOTLB turned on - which meant 64MB of precious contingous DMA32 memory being eaten up per guest). The problem was: "on xen we add an extra memory region at the end of the e820, and on this particular machine this extra memory region would start below 4g and cross over the 4g boundary: [0xfee01000-0x192655000) Unfortunately e820_end_of_low_ram_pfn does not expect an e820 layout like that so it returns 4g, therefore initial_memory_mapping will map [0 - 0x100000000), that is a memory range that includes some reserved memory regions." The memory range was the IOAPIC regions, and with the 1-1 mapping turned on, it would map them as RAM, not as MMIO regions. This caused the hypervisor to complain. Fortunately this is experienced only under the initial domain so we guard for it. Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-06-15xen: When calling power_off, don't call the halt function.Tom Goetz
.. As it won't actually power off the machine. Reported-by: Sven Köhler <sven.koehler@gmail.com> Tested-by: Sven Köhler <sven.koehler@gmail.com> Signed-off-by: Tom Goetz <tom.goetz@virtualcomputer.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-06-15xen: support CONFIG_MAXSMPAndrew Jones
The MAXSMP config option requires CPUMASK_OFFSTACK, which in turn requires we init the memory for the maps while we bring up the cpus. MAXSMP also increases NR_CPUS to 4096. This increase in size exposed an issue in the argument construction for multicalls from xen_flush_tlb_others. The args should only need space for the actual number of cpus. Also in 2.6.39 it exposes a bootup problem. BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff8157a1d3>] set_cpu_sibling_map+0x123/0x30d ... Call Trace: [<ffffffff81039a3f>] ? xen_restore_fl_direct_reloc+0x4/0x4 [<ffffffff819dc4db>] xen_smp_prepare_cpus+0x36/0x135 .. CC: stable@kernel.org Signed-off-by: Andrew Jones <drjones@redhat.com> [v2: Updated to compile on 3.0] [v3: Updated to compile when CONFIG_SMP is not defined] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-06-09xen: partially revert "xen: set max_pfn_mapped to the last pfn mapped"Stefano Stabellini
We only need to set max_pfn_mapped to the last pfn mapped on x86_64 to make sure that cleanup_highmap doesn't remove important mappings at _end. We don't need to do this on x86_32 because cleanup_highmap is not called on x86_32. Besides lowering max_pfn_mapped on x86_32 has the unwanted side effect of limiting the amount of memory available for the 1:1 kernel pagetable allocation. This patch reverts the x86_32 part of the original patch. CC: stable@kernel.org Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-06-03xen: off by one errors in multicalls.cDan Carpenter
b->args[] has MC_ARGS elements, so the comparison here should be ">=" instead of ">". Otherwise we read past the end of the array one space. CC: stable@kernel.org Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-05-26Merge branch 'upstream/tidy-xen-mmu-2.6.39' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen * 'upstream/tidy-xen-mmu-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen: xen: fix compile without CONFIG_XEN_DEBUG_FS Use arbitrary_virt_to_machine() to deal with ioremapped pud updates. Use arbitrary_virt_to_machine() to deal with ioremapped pmd updates. xen/mmu: remove all ad-hoc stats stuff xen: use normal virt_to_machine for ptes xen: make a pile of mmu pvop functions static vmalloc: remove vmalloc_sync_all() from alloc_vm_area() xen: condense everything onto xen_set_pte xen: use mmu_update for xen_set_pte_at() xen: drop all the special iomap pte paths.
2011-05-23Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits) b43: fix comment typo reqest -> request Haavard Skinnemoen has left Atmel cris: typo in mach-fs Makefile Kconfig: fix copy/paste-ism for dell-wmi-aio driver doc: timers-howto: fix a typo ("unsgined") perf: Only include annotate.h once in tools/perf/util/ui/browsers/annotate.c md, raid5: Fix spelling error in comment ('Ofcourse' --> 'Of course'). treewide: fix a few typos in comments regulator: change debug statement be consistent with the style of the rest Revert "arm: mach-u300/gpio: Fix mem_region resource size miscalculations" audit: acquire creds selectively to reduce atomic op overhead rtlwifi: don't touch with treewide double semicolon removal treewide: cleanup continuations and remove logging message whitespace ath9k_hw: don't touch with treewide double semicolon removal include/linux/leds-regulator.h: fix syntax in example code tty: fix typo in descripton of tty_termios_encode_baud_rate xtensa: remove obsolete BKL kernel option from defconfig m68k: fix comment typo 'occcured' arch:Kconfig.locks Remove unused config option. treewide: remove extra semicolons ...
2011-05-20xen: fix compile without CONFIG_XEN_DEBUG_FSJeremy Fitzhardinge
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-05-20Use arbitrary_virt_to_machine() to deal with ioremapped pud updates.Jeremy Fitzhardinge
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-05-20Use arbitrary_virt_to_machine() to deal with ioremapped pmd updates.Jeremy Fitzhardinge
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-05-20xen/mmu: remove all ad-hoc stats stuffJeremy Fitzhardinge
To make way for tracing. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-05-20xen: use normal virt_to_machine for ptesJeremy Fitzhardinge
We no longer support HIGHPTE allocations, so ptes should always be within the kernel's direct map, and don't need pagetable walks to convert to machine addresses. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-05-20xen: make a pile of mmu pvop functions staticJeremy Fitzhardinge
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-05-20xen: condense everything onto xen_set_pteJeremy Fitzhardinge
xen_set_pte_at and xen_clear_pte are essentially identical to xen_set_pte, so just make them all common. When batched set_pte and pte_clear are the same, but the unbatch operation must be different: they need to update the two halves of the pte in different order. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-05-20xen: use mmu_update for xen_set_pte_at()Jeremy Fitzhardinge
In principle update_va_mapping is a good match for set_pte_at, since it gets the address being mapped, which allows Xen to use its linear pagetable mapping. However that assumes that the pmd for the address is attached to the current pagetable, which may not be true for a given user address space because the kernel pmd is not shared (at least on 32-bit guests). Normally the kernel will automatically sync a missing part of the pagetable with the init_mm pagetable transparently via faults, but that fails when a missing address is passed to Xen. And while the linear pagetable mapping is very useful for 32-bit Xen (as it avoids an explicit domain mapping), 32-bit Xen is deprecated. 64-bit Xen has all memory mapped all the time, so it makes no real difference. The upshot is that we should use mmu_update, since it can operate on non-current pagetables or detached pagetables. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-05-20xen: drop all the special iomap pte paths.Jeremy Fitzhardinge
Xen can work out when we're doing IO mappings for itself, so we don't need to do anything special, and the extra tests just clog things up. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-05-19Merge branch 'timers-clocksource-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-clocksource-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: clocksource: convert mips to generic i8253 clocksource clocksource: convert x86 to generic i8253 clocksource clocksource: convert footbridge to generic i8253 clocksource clocksource: add common i8253 PIT clocksource blackfin: convert to clocksource_register_hz mips: convert to clocksource_register_hz/khz sparc: convert to clocksource_register_hz/khz alpha: convert to clocksource_register_hz microblaze: convert to clocksource_register_hz/khz ia64: convert to clocksource_register_hz/khz x86: Convert remaining x86 clocksources to clocksource_register_hz/khz Make clocksource name const
2011-05-19Merge branches 'sched-core-for-linus' and 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (60 commits) sched: Fix and optimise calculation of the weight-inverse sched: Avoid going ahead if ->cpus_allowed is not changed sched, rt: Update rq clock when unthrottling of an otherwise idle CPU sched: Remove unused parameters from sched_fork() and wake_up_new_task() sched: Shorten the construction of the span cpu mask of sched domain sched: Wrap the 'cfs_rq->nr_spread_over' field with CONFIG_SCHED_DEBUG sched: Remove unused 'this_best_prio arg' from balance_tasks() sched: Remove noop in alloc_rt_sched_group() sched: Get rid of lock_depth sched: Remove obsolete comment from scheduler_tick() sched: Fix sched_domain iterations vs. RCU sched: Next buddy hint on sleep and preempt path sched: Make set_*_buddy() work on non-task entities sched: Remove need_migrate_task() sched: Move the second half of ttwu() to the remote cpu sched: Restructure ttwu() some more sched: Rename ttwu_post_activation() to ttwu_do_wakeup() sched: Remove rq argument from ttwu_stat() sched: Remove rq->lock from the first half of ttwu() sched: Drop rq->lock from sched_exec() ... * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Fix rt_rq runtime leakage bug
2011-05-19Merge branches 'stable/irq', 'stable/p2m.bugfixes', 'stable/e820.bugfixes' ↵Linus Torvalds
and 'stable/mmu.bugfixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen * 'stable/irq' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen: do not clear and mask evtchns in __xen_evtchn_do_upcall * 'stable/p2m.bugfixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/p2m: Create entries in the P2M_MFN trees's to track 1-1 mappings * 'stable/e820.bugfixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/setup: Fix for incorrect xen_extra_mem_start initialization under 32-bit xen/setup: Ignore E820_UNUSABLE when setting 1-1 mappings. * 'stable/mmu.bugfixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen mmu: fix a race window causing leave_mm BUG()
2011-05-19Merge branches 'stable/balloon.cleanup' and 'stable/general.cleanup' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen * 'stable/balloon.cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/balloon: Move dec_totalhigh_pages() from __balloon_append() to balloon_append() xen/balloon: Clarify credit calculation xen/balloon: Simplify HVM integration xen/balloon: Use PageHighMem() for high memory page detection * 'stable/general.cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: drivers/xen/sys-hypervisor: Cleanup code/data sections definitions arch/x86/xen/smp: Cleanup code/data sections definitions arch/x86/xen/time: Cleanup code/data sections definitions arch/x86/xen/xen-ops: Cleanup code/data sections definitions arch/x86/xen/mmu: Cleanup code/data sections definitions arch/x86/xen/setup: Cleanup code/data sections definitions arch/x86/xen/enlighten: Cleanup code/data sections definitions arch/x86/xen/irq: Cleanup code/data sections definitions xen: tidy up whitespace in drivers/xen/Makefile
2011-05-19Merge branches 'stable/backend.base.v3' and 'stable/gntalloc.v7' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen * 'stable/backend.base.v3' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/pci: Fix compiler error when CONFIG_XEN_PRIVILEGED_GUEST is not set. xen/p2m: Add EXPORT_SYMBOL_GPL to the M2P override functions. xen/p2m/m2p/gnttab: Support GNTMAP_host_map in the M2P override. xen/irq: The Xen hypervisor cleans up the PIRQs if the other domain forgot. xen/irq: Export 'xen_pirq_from_irq' function. xen/irq: Add support to check if IRQ line is shared with other domains. xen/irq: Check if the PCI device is owned by a domain different than DOMID_SELF. xen/pci: Add xen_[find|register|unregister]_device_domain_owner functions. * 'stable/gntalloc.v7' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/gntdev,gntalloc: Remove unneeded VM flags
2011-05-19arch/x86/xen/smp: Cleanup code/data sections definitionsDaniel Kiper
Cleanup code/data sections definitions accordingly to include/linux/init.h. Signed-off-by: Daniel Kiper <dkiper@net-space.pl> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-19arch/x86/xen/time: Cleanup code/data sections definitionsDaniel Kiper
Cleanup code/data sections definitions accordingly to include/linux/init.h. Signed-off-by: Daniel Kiper <dkiper@net-space.pl> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-19arch/x86/xen/xen-ops: Cleanup code/data sections definitionsDaniel Kiper
Cleanup code/data sections definitions accordingly to include/linux/init.h. Signed-off-by: Daniel Kiper <dkiper@net-space.pl> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-19arch/x86/xen/mmu: Cleanup code/data sections definitionsDaniel Kiper
Cleanup code/data sections definitions accordingly to include/linux/init.h. Signed-off-by: Daniel Kiper <dkiper@net-space.pl> [v1: Rebased on top of latest linus's to include fixes in mmu.c] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-14Merge branch 'consolidate-clksrc-i8253' of ↵Thomas Gleixner
master.kernel.org:~rmk/linux-2.6-arm into timers/clocksource Conflicts: arch/ia64/kernel/cyclone.c arch/mips/kernel/i8253.c arch/x86/kernel/i8253.c Reason: Resolve conflicts so further cleanups do not conflict further Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-05-12arch/x86/xen/setup: Cleanup code/data sections definitionsDaniel Kiper
Cleanup code/data sections definitions accordingly to include/linux/init.h. Signed-off-by: Daniel Kiper <dkiper@net-space.pl> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12arch/x86/xen/enlighten: Cleanup code/data sections definitionsDaniel Kiper
Cleanup code/data sections definitions accordingly to include/linux/init.h. Signed-off-by: Daniel Kiper <dkiper@net-space.pl> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12arch/x86/xen/irq: Cleanup code/data sections definitionsDaniel Kiper
Cleanup code/data sections definitions accordingly to include/linux/init.h. Signed-off-by: Daniel Kiper <dkiper@net-space.pl> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12xen/p2m: Create entries in the P2M_MFN trees's to track 1-1 mappingsKonrad Rzeszutek Wilk
.. when applicable. We need to track in the p2m_mfn and p2m_mfn_p the MFNs and pointers, respectivly, for the P2M entries that are allocated for the identity mappings. Without this, a PV domain with an E820 that triggers the 1-1 mapping to kick in, won't be able to be restored as the P2M won't have the identity mappings. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12xen/setup: Fix for incorrect xen_extra_mem_start initialization under 32-bitDaniel Kiper
git commit 24bdb0b62cc82120924762ae6bc85afc8c3f2b26 (xen: do not create the extra e820 region at an addr lower than 4G) does not take into account that ifdef CONFIG_X86_32 instead of e820_end_of_low_ram_pfn() find_low_pfn_range() is called (both calls are from arch/x86/kernel/setup.c). find_low_pfn_range() behaves correctly and does not require change in xen_extra_mem_start initialization. Additionally, if xen_extra_mem_start is initialized in the same way as ifdef CONFIG_X86_64 then memory hotplug support for Xen balloon driver (under development) is broken. Signed-off-by: Daniel Kiper <dkiper@net-space.pl> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>