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2012-11-12KVM: x86: invalid opcode oops on SET_SREGS with OSXSAVE bit set (CVE-2012-4461)Petr Matousek
On hosts without the XSAVE support unprivileged local user can trigger oops similar to the one below by setting X86_CR4_OSXSAVE bit in guest cr4 register using KVM_SET_SREGS ioctl and later issuing KVM_RUN ioctl. invalid opcode: 0000 [#2] SMP Modules linked in: tun ip6table_filter ip6_tables ebtable_nat ebtables ... Pid: 24935, comm: zoog_kvm_monito Tainted: G D 3.2.0-3-686-pae EIP: 0060:[<f8b9550c>] EFLAGS: 00210246 CPU: 0 EIP is at kvm_arch_vcpu_ioctl_run+0x92a/0xd13 [kvm] EAX: 00000001 EBX: 000f387e ECX: 00000000 EDX: 00000000 ESI: 00000000 EDI: 00000000 EBP: ef5a0060 ESP: d7c63e70 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 Process zoog_kvm_monito (pid: 24935, ti=d7c62000 task=ed84a0c0 task.ti=d7c62000) Stack: 00000001 f70a1200 f8b940a9 ef5a0060 00000000 00200202 f8769009 00000000 ef5a0060 000f387e eda5c020 8722f9c8 00015bae 00000000 ed84a0c0 ed84a0c0 c12bf02d 0000ae80 ef7f8740 fffffffb f359b740 ef5a0060 f8b85dc1 0000ae80 Call Trace: [<f8b940a9>] ? kvm_arch_vcpu_ioctl_set_sregs+0x2fe/0x308 [kvm] ... [<c12bfb44>] ? syscall_call+0x7/0xb Code: 89 e8 e8 14 ee ff ff ba 00 00 04 00 89 e8 e8 98 48 ff ff 85 c0 74 1e 83 7d 48 00 75 18 8b 85 08 07 00 00 31 c9 8b 95 0c 07 00 00 <0f> 01 d1 c7 45 48 01 00 00 00 c7 45 1c 01 00 00 00 0f ae f0 89 EIP: [<f8b9550c>] kvm_arch_vcpu_ioctl_run+0x92a/0xd13 [kvm] SS:ESP 0068:d7c63e70 QEMU first retrieves the supported features via KVM_GET_SUPPORTED_CPUID and then sets them later. So guest's X86_FEATURE_XSAVE should be masked out on hosts without X86_FEATURE_XSAVE, making kvm_set_cr4 with X86_CR4_OSXSAVE fail. Userspaces that allow specifying guest cpuid with X86_FEATURE_XSAVE even on hosts that do not support it, might be susceptible to this attack from inside the guest as well. Allow setting X86_CR4_OSXSAVE bit only if host has XSAVE support. Signed-off-by: Petr Matousek <pmatouse@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-10-31KVM: x86: fix vcpu->mmio_fragments overflowXiao Guangrong
After commit b3356bf0dbb349 (KVM: emulator: optimize "rep ins" handling), the pieces of io data can be collected and write them to the guest memory or MMIO together Unfortunately, kvm splits the mmio access into 8 bytes and store them to vcpu->mmio_fragments. If the guest uses "rep ins" to move large data, it will cause vcpu->mmio_fragments overflow The bug can be exposed by isapc (-M isapc): [23154.818733] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC [ ......] [23154.858083] Call Trace: [23154.859874] [<ffffffffa04f0e17>] kvm_get_cr8+0x1d/0x28 [kvm] [23154.861677] [<ffffffffa04fa6d4>] kvm_arch_vcpu_ioctl_run+0xcda/0xe45 [kvm] [23154.863604] [<ffffffffa04f5a1a>] ? kvm_arch_vcpu_load+0x17b/0x180 [kvm] Actually, we can use one mmio_fragment to store a large mmio access then split it when we pass the mmio-exit-info to userspace. After that, we only need two entries to store mmio info for the cross-mmio pages access Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-10-04Merge tag 'kvm-3.7-1' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Avi Kivity: "Highlights of the changes for this release include support for vfio level triggered interrupts, improved big real mode support on older Intels, a streamlines guest page table walker, guest APIC speedups, PIO optimizations, better overcommit handling, and read-only memory." * tag 'kvm-3.7-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (138 commits) KVM: s390: Fix vcpu_load handling in interrupt code KVM: x86: Fix guest debug across vcpu INIT reset KVM: Add resampling irqfds for level triggered interrupts KVM: optimize apic interrupt delivery KVM: MMU: Eliminate pointless temporary 'ac' KVM: MMU: Avoid access/dirty update loop if all is well KVM: MMU: Eliminate eperm temporary KVM: MMU: Optimize is_last_gpte() KVM: MMU: Simplify walk_addr_generic() loop KVM: MMU: Optimize pte permission checks KVM: MMU: Update accessed and dirty bits after guest pagetable walk KVM: MMU: Move gpte_access() out of paging_tmpl.h KVM: MMU: Optimize gpte_access() slightly KVM: MMU: Push clean gpte write protection out of gpte_access() KVM: clarify kvmclock documentation KVM: make processes waiting on vcpu mutex killable KVM: SVM: Make use of asm.h KVM: VMX: Make use of asm.h KVM: VMX: Make lto-friendly KVM: x86: lapic: Clean up find_highest_vector() and count_vectors() ... Conflicts: arch/s390/include/asm/processor.h arch/x86/kvm/i8259.c
2012-10-01Merge branch 'x86-fpu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86/fpu update from Ingo Molnar: "The biggest change is the addition of the non-lazy (eager) FPU saving support model and enabling it on CPUs with optimized xsaveopt/xrstor FPU state saving instructions. There are also various Sparse fixes" Fix up trivial add-add conflict in arch/x86/kernel/traps.c * 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, kvm: fix kvm's usage of kernel_fpu_begin/end() x86, fpu: remove cpu_has_xmm check in the fx_finit() x86, fpu: make eagerfpu= boot param tri-state x86, fpu: enable eagerfpu by default for xsaveopt x86, fpu: decouple non-lazy/eager fpu restore from xsave x86, fpu: use non-lazy fpu restore for processors supporting xsave lguest, x86: handle guest TS bit for lazy/non-lazy fpu host models x86, fpu: always use kernel_fpu_begin/end() for in-kernel FPU usage x86, kvm: use kernel_fpu_begin/end() in kvm_load/put_guest_fpu() x86, fpu: remove unnecessary user_fpu_end() in save_xstate_sig() x86, fpu: drop_fpu() before restoring new state from sigframe x86, fpu: Unify signal handling code paths for x86 and x86_64 kernels x86, fpu: Consolidate inline asm routines for saving/restoring fpu state x86, signal: Cleanup ifdefs and is_ia32, is_x32
2012-09-23KVM: x86: Fix guest debug across vcpu INIT resetJan Kiszka
If we reset a vcpu on INIT, we so far overwrote dr7 as provided by KVM_SET_GUEST_DEBUG, and we also cleared switch_db_regs unconditionally. Fix this by saving the dr7 used for guest debugging and calculating the effective register value as well as switch_db_regs on any potential change. This will change to focus of the set_guest_debug vendor op to update_dp_bp_intercept. Found while trying to stop on start_secondary. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-23KVM: Add resampling irqfds for level triggered interruptsAlex Williamson
To emulate level triggered interrupts, add a resample option to KVM_IRQFD. When specified, a new resamplefd is provided that notifies the user when the irqchip has been resampled by the VM. This may, for instance, indicate an EOI. Also in this mode, posting of an interrupt through an irqfd only asserts the interrupt. On resampling, the interrupt is automatically de-asserted prior to user notification. This enables level triggered interrupts to be posted and re-enabled from vfio with no userspace intervention. All resampling irqfds can make use of a single irq source ID, so we reserve a new one for this interface. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-21x86, kvm: fix kvm's usage of kernel_fpu_begin/end()Suresh Siddha
Preemption is disabled between kernel_fpu_begin/end() and as such it is not a good idea to use these routines in kvm_load/put_guest_fpu() which can be very far apart. kvm_load/put_guest_fpu() routines are already called with preemption disabled and KVM already uses the preempt notifier to save the guest fpu state using kvm_put_guest_fpu(). So introduce __kernel_fpu_begin/end() routines which don't touch preemption and use them instead of kernel_fpu_begin/end() for KVM's use model of saving/restoring guest FPU state. Also with this change (and with eagerFPU model), fix the host cr0.TS vm-exit state in the case of VMX. For eagerFPU case, host cr0.TS is always clear. So no need to worry about it. For the traditional lazyFPU restore case, change the cr0.TS bit for the host state during vm-exit to be always clear and cr0.TS bit is set in the __vmx_load_host_state() when the FPU (guest FPU or the host task's FPU) state is not active. This ensures that the host/guest FPU state is properly saved, restored during context-switch and with interrupts (using irq_fpu_usable()) not stomping on the active FPU state. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1348164109.26695.338.camel@sbsiddha-desk.sc.intel.com Cc: Avi Kivity <avi@redhat.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-09-20KVM: optimize apic interrupt deliveryGleb Natapov
Most interrupt are delivered to only one vcpu. Use pre-build tables to find interrupt destination instead of looping through all vcpus. In case of logical mode loop only through vcpus in a logical cluster irq is sent to. Signed-off-by: Gleb Natapov <gleb@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-20KVM: MMU: Optimize pte permission checksAvi Kivity
walk_addr_generic() permission checks are a maze of branchy code, which is performed four times per lookup. It depends on the type of access, efer.nxe, cr0.wp, cr4.smep, and in the near future, cr4.smap. Optimize this away by precalculating all variants and storing them in a bitmap. The bitmap is recalculated when rarely-changing variables change (cr0, cr4) and is indexed by the often-changing variables (page fault error code, pte access permissions). The permission check is moved to the end of the loop, otherwise an SMEP fault could be reported as a false positive, when PDE.U=1 but PTE.U=0. Noted by Xiao Guangrong. The result is short, branch-free code. Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-18x86, kvm: use kernel_fpu_begin/end() in kvm_load/put_guest_fpu()Suresh Siddha
kvm's guest fpu save/restore should be wrapped around kernel_fpu_begin/end(). This will avoid for example taking a DNA in kvm_load_guest_fpu() when it tries to load the fpu immediately after doing unlazy_fpu() on the host side. More importantly this will prevent the host process fpu from being corrupted. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1345842782-24175-4-git-send-email-suresh.b.siddha@intel.com Cc: Avi Kivity <avi@redhat.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-09-17KVM: make processes waiting on vcpu mutex killableMichael S. Tsirkin
vcpu mutex can be held for unlimited time so taking it with mutex_lock on an ioctl is wrong: one process could be passed a vcpu fd and call this ioctl on the vcpu used by another process, it will then be unkillable until the owner exits. Call mutex_lock_killable instead and return status. Note: mutex_lock_interruptible would be even nicer, but I am not sure all users are prepared to handle EINTR from these ioctls. They might misinterpret it as an error. Cleanup paths expect a vcpu that can't be used by any userspace so this will always succeed - catch bugs by calling BUG_ON. Catch callers that don't check return state by adding __must_check. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-09-10KVM: fix error paths for failed gfn_to_page() callsXiao Guangrong
This bug was triggered: [ 4220.198458] BUG: unable to handle kernel paging request at fffffffffffffffe [ 4220.203907] IP: [<ffffffff81104d85>] put_page+0xf/0x34 ...... [ 4220.237326] Call Trace: [ 4220.237361] [<ffffffffa03830d0>] kvm_arch_destroy_vm+0xf9/0x101 [kvm] [ 4220.237382] [<ffffffffa036fe53>] kvm_put_kvm+0xcc/0x127 [kvm] [ 4220.237401] [<ffffffffa03702bc>] kvm_vcpu_release+0x18/0x1c [kvm] [ 4220.237407] [<ffffffff81145425>] __fput+0x111/0x1ed [ 4220.237411] [<ffffffff8114550f>] ____fput+0xe/0x10 [ 4220.237418] [<ffffffff81063511>] task_work_run+0x5d/0x88 [ 4220.237424] [<ffffffff8104c3f7>] do_exit+0x2bf/0x7ca The test case: printf(fmt, ##args); \ exit(-1);} while (0) static int create_vm(void) { int sys_fd, vm_fd; sys_fd = open("/dev/kvm", O_RDWR); if (sys_fd < 0) die("open /dev/kvm fail.\n"); vm_fd = ioctl(sys_fd, KVM_CREATE_VM, 0); if (vm_fd < 0) die("KVM_CREATE_VM fail.\n"); return vm_fd; } static int create_vcpu(int vm_fd) { int vcpu_fd; vcpu_fd = ioctl(vm_fd, KVM_CREATE_VCPU, 0); if (vcpu_fd < 0) die("KVM_CREATE_VCPU ioctl.\n"); printf("Create vcpu.\n"); return vcpu_fd; } static void *vcpu_thread(void *arg) { int vm_fd = (int)(long)arg; create_vcpu(vm_fd); return NULL; } int main(int argc, char *argv[]) { pthread_t thread; int vm_fd; (void)argc; (void)argv; vm_fd = create_vm(); pthread_create(&thread, NULL, vcpu_thread, (void *)(long)vm_fd); printf("Exit.\n"); return 0; } It caused by release kvm->arch.ept_identity_map_addr which is the error page. The parent thread can send KILL signal to the vcpu thread when it was exiting which stops faulting pages and potentially allocating memory. So gfn_to_pfn/gfn_to_page may fail at this time Fixed by checking the page before it is used Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-06KVM: use symbolic constant for nr interruptsMichael S. Tsirkin
interrupt_bitmap is KVM_NR_INTERRUPTS bits in size, so just use that instead of hard-coded constants and math. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-06KVM: Provide userspace IO exit completion callbackGleb Natapov
Current code assumes that IO exit was due to instruction emulation and handles execution back to emulator directly. This patch adds new userspace IO exit completion callback that can be set by any other code that caused IO exit to userspace. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-06KVM: move postcommit flush to x86, as mmio sptes are x86 specificMarcelo Tosatti
Other arches do not need this. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> v2: fix incorrect deletion of mmio sptes on gpa move (noticed by Takuya) Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-06KVM: split kvm_arch_flush_shadowMarcelo Tosatti
Introducing kvm_arch_flush_shadow_memslot, to invalidate the translations of a single memory slot. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-05KVM: x86: more constificationMathias Krause
Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-05KVM: x86: constify read_write_emulator_opsMathias Krause
We never change those, make them r/o. Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-05KVM: x86 emulator: constify emulate_opsMathias Krause
We never change emulate_ops[] at runtime so it should be r/o. Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-30KVM: x86: remove unused variable from kvm_task_switch()Marcelo Tosatti
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-27KVM: x86 emulator: access GPRs on demandAvi Kivity
Instead of populating the entire register file, read in registers as they are accessed, and write back only the modified ones. This saves a VMREAD and VMWRITE on Intel (for rsp, since it is not usually used during emulation), and a two 128-byte copies for the registers. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-27KVM: x86: fix KVM_GET_MSR for PV EOIMichael S. Tsirkin
KVM_GET_MSR was missing support for PV EOI, which is needed for migration. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-22KVM: introduce readonly memslotXiao Guangrong
In current code, if we map a readonly memory space from host to guest and the page is not currently mapped in the host, we will get a fault pfn and async is not allowed, then the vm will crash We introduce readonly memory region to map ROM/ROMD to the guest, read access is happy for readonly memslot, write access on readonly memslot will cause KVM_EXIT_MMIO exit Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-22KVM: x86: fix possible infinite loop caused by reexecute_instructionXiao Guangrong
Currently, we reexecute all unhandleable instructions if they do not access on the mmio, however, it can not work if host map the readonly memory to guest. If the instruction try to write this kind of memory, it will fault again when guest retry it, then we will goto a infinite loop: retry instruction -> write #PF -> emulation fail -> retry instruction -> ... Fix it by retrying the instruction only when it faults on the writable memory Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-13KVM: x86: fix pvclock guest stopped flag reportingMarcelo Tosatti
kvm_guest_time_update unconditionally clears hv_clock.flags field, so the notification never reaches the guest. Fix it by allowing PVCLOCK_GUEST_STOPPED to passthrough. Reviewed-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-09KVM: correctly detect APIC SW state in kvm_apic_post_state_restore()Gleb Natapov
For apic_set_spiv() to track APIC SW state correctly it needs to see previous and next values of the spurious vector register, but currently memset() overwrite the old value before apic_set_spiv() get a chance to do tracking. Fix it by calling apic_set_spiv() before overwriting old value. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06KVM: use jump label to optimize checking for in kernel local apic presenceGleb Natapov
Usually all vcpus have local apic pointer initialized, so the check may be completely skipped. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06KVM: use jump label to optimize checking for HW enabled APIC in APIC_BASE MSRGleb Natapov
Usually all APICs are HW enabled so the check can be optimized out. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06KVM: clean up kvm_(set|get)_apic_baseGleb Natapov
kvm_get_apic_base() needlessly checks irqchip_in_kernel although it does the same no matter what result of the check is. kvm_set_apic_base() also checks for irqchip_in_kernel, but kvm_lapic_set_base() can handle this case. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06KVM: do not release the error pageXiao Guangrong
After commit a2766325cf9f9, the error page is replaced by the error code, it need not be released anymore [ The patch has been compiling tested for powerpc ] Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06KVM: Push rmap into kvm_arch_memory_slotTakuya Yoshikawa
Two reasons: - x86 can integrate rmap and rmap_pde and remove heuristics in __gfn_to_rmap(). - Some architectures do not need rmap. Since rmap is one of the most memory consuming stuff in KVM, ppc'd better restrict the allocation to Book3S HV. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06KVM: Stop checking rmap to see if slot is being createdTakuya Yoshikawa
Instead, check npages consistently. This helps to make rmap architecture specific in a later patch. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-05KVM: x86: update KVM_SAVE_MSRS_BEGIN to correct valueGleb Natapov
When MSR_KVM_PV_EOI_EN was added to msrs_to_save array KVM_SAVE_MSRS_BEGIN was not updated accordingly. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-05Merge remote-tracking branch 'upstream' into nextAvi Kivity
- bring back critical fixes (esp. aa67f6096c19bc) - provide an updated base for development * upstream: (4334 commits) missed mnt_drop_write() in do_dentry_open() UBIFS: nuke pdflush from comments gfs2: nuke pdflush from comments drbd: nuke pdflush from comments nilfs2: nuke write_super from comments hfs: nuke write_super from comments vfs: nuke pdflush from comments jbd/jbd2: nuke write_super from comments btrfs: nuke pdflush from comments btrfs: nuke write_super from comments ext4: nuke pdflush from comments ext4: nuke write_super from comments ext3: nuke write_super from comments Documentation: fix the VM knobs descritpion WRT pdflush Documentation: get rid of write_super vfs: kill write_super and sync_supers ACPI processor: Fix tick_broadcast_mask online/offline regression ACPI: Only count valid srat memory structures ACPI: Untangle a return statement for better readability Linux 3.6-rc1 ... Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-03KVM: x86: update KVM_SAVE_MSRS_BEGIN to correct valueGleb Natapov
When MSR_KVM_PV_EOI_EN was added to msrs_to_save array KVM_SAVE_MSRS_BEGIN was not updated accordingly. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-01KVM: x86: apply kvmclock offset to guest wall clock timeBruce Rogers
When a guest migrates to a new host, the system time difference from the previous host is used in the updates to the kvmclock system time visible to the guest, resulting in a continuation of correct kvmclock based guest timekeeping. The wall clock component of the kvmclock provided time is currently not updated with this same time offset. Since the Linux guest caches the wall clock based time, this discrepency is not noticed until the guest is rebooted. After reboot the guest's time calculations are off. This patch adjusts the wall clock by the kvmclock_offset, resulting in correct guest time after a reboot. Cc: Zachary Amsden <zamsden@gmail.com> Signed-off-by: Bruce Rogers <brogers@suse.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-01KVM: fold kvm_pit_timer into kvm_kpit_stateAvi Kivity
One structure nests inside the other, providing no value at all. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-26KVM: Move KVM_IRQ_LINE to arch-generic codeChristoffer Dall
Handle KVM_IRQ_LINE and KVM_IRQ_LINE_STATUS in the generic kvm_vm_ioctl() function and call into kvm_vm_ioctl_irq_line(). This is even more relevant when KVM/ARM also uses this ioctl. Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-20KVM: x86: Fix typos in x86.cGuo Chao
Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-19KVM: x86: remove unnecessary mark_page_dirtyXiao Guangrong
fix: [ 132.474633] 3.5.0-rc1+ #50 Not tainted [ 132.474634] ------------------------------- [ 132.474635] include/linux/kvm_host.h:369 suspicious rcu_dereference_check() usage! [ 132.474636] [ 132.474636] other info that might help us debug this: [ 132.474636] [ 132.474638] [ 132.474638] rcu_scheduler_active = 1, debug_locks = 1 [ 132.474640] 1 lock held by qemu-kvm/2832: [ 132.474657] #0: (&vcpu->mutex){+.+.+.}, at: [<ffffffffa01e1636>] vcpu_load+0x1e/0x91 [kvm] [ 132.474658] [ 132.474658] stack backtrace: [ 132.474660] Pid: 2832, comm: qemu-kvm Not tainted 3.5.0-rc1+ #50 [ 132.474661] Call Trace: [ 132.474665] [<ffffffff81092f40>] lockdep_rcu_suspicious+0xfc/0x105 [ 132.474675] [<ffffffffa01e0c85>] kvm_memslots+0x6d/0x75 [kvm] [ 132.474683] [<ffffffffa01e0ca1>] gfn_to_memslot+0x14/0x4c [kvm] [ 132.474693] [<ffffffffa01e3575>] mark_page_dirty+0x17/0x2a [kvm] [ 132.474706] [<ffffffffa01f21ea>] kvm_arch_vcpu_ioctl+0xbcf/0xc07 [kvm] Actually, we do not write vcpu->arch.time at this time, mark_page_dirty should be removed. Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-18KVM: Separate rmap_pde from kvm_lpage_info->write_countTakuya Yoshikawa
This makes it possible to loop over rmap_pde arrays in the same way as we do over rmap so that we can optimize kvm_handle_hva_range() easily in the following patch. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-12KVM: VMX: Implement PCID/INVPCID for guests with EPTMao, Junjie
This patch handles PCID/INVPCID for guests. Process-context identifiers (PCIDs) are a facility by which a logical processor may cache information for multiple linear-address spaces so that the processor may retain cached information when software switches to a different linear address space. Refer to section 4.10.1 in IA32 Intel Software Developer's Manual Volume 3A for details. For guests with EPT, the PCID feature is enabled and INVPCID behaves as running natively. For guests without EPT, the PCID feature is disabled and INVPCID triggers #UD. Signed-off-by: Junjie Mao <junjie.mao@intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-09KVM: x86 emulator: change ->get_cpuid() accessor to use the x86 semanticsAvi Kivity
Instead of getting an exact leaf, follow the spec and fall back to the last main leaf instead. This lets us easily emulate the cpuid instruction in the emulator. Signed-off-by: Avi Kivity <avi@redhat.com>
2012-06-25KVM: host side for eoi optimizationMichael S. Tsirkin
Implementation of PV EOI using shared memory. This reduces the number of exits an interrupt causes as much as by half. The idea is simple: there's a bit, per APIC, in guest memory, that tells the guest that it does not need EOI. We set it before injecting an interrupt and clear before injecting a nested one. Guest tests it using a test and clear operation - this is necessary so that host can detect interrupt nesting - and if set, it can skip the EOI MSR. There's a new MSR to set the address of said register in guest memory. Otherwise not much changed: - Guest EOI is not required - Register is tested & ISR is automatically cleared on exit For testing results see description of previous patch 'kvm_para: guest side for eoi avoidance'. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-06-25KVM: rearrange injection cancelling codeMichael S. Tsirkin
Each time we need to cancel injection we invoke same code (cancel_injection callback). Move it towards the end of function using the familiar goto on error pattern. Will make it easier to do more cleanups for PV EOI. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-06-25KVM: only sync when attention bits setMichael S. Tsirkin
Commit eb0dc6d0368072236dcd086d7fdc17fd3c4574d4 introduced apic attention bitmask but kvm still syncs lapic unconditionally. As that commit suggested and in anticipation of adding more attention bits, only sync lapic if(apic_attention). Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-06-19KVM: Use kvm_kvfree() to free memory allocated by kvm_kvzalloc()Takuya Yoshikawa
The following commit did not care about the error handling path: commit c1a7b32a14138f908df52d7c53b5ce3415ec6b50 KVM: Avoid wasting pages for small lpage_info arrays If memory allocation fails, vfree() will be called with the address returned by kzalloc(). This patch fixes this issue. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-06-06KVM: Cleanup the kvm_print functions and introduce pr_XX wrappersChristoffer Dall
Introduces a couple of print functions, which are essentially wrappers around standard printk functions, with a KVM: prefix. Functions introduced or modified are: - kvm_err(fmt, ...) - kvm_info(fmt, ...) - kvm_debug(fmt, ...) - kvm_pr_unimpl(fmt, ...) - pr_unimpl(vcpu, fmt, ...) -> vcpu_unimpl(vcpu, fmt, ...) Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-06-05KVM: Avoid wasting pages for small lpage_info arraysTakuya Yoshikawa
lpage_info is created for each large level even when the memory slot is not for RAM. This means that when we add one slot for a PCI device, we end up allocating at least KVM_NR_PAGE_SIZES - 1 pages by vmalloc(). To make things worse, there is an increasing number of devices which would result in more pages being wasted this way. This patch mitigates this problem by using kvm_kvzalloc(). Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-05-24Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM changes from Avi Kivity: "Changes include additional instruction emulation, page-crossing MMIO, faster dirty logging, preventing the watchdog from killing a stopped guest, module autoload, a new MSI ABI, and some minor optimizations and fixes. Outside x86 we have a small s390 and a very large ppc update. Regarding the new (for kvm) rebaseless workflow, some of the patches that were merged before we switch trees had to be rebased, while others are true pulls. In either case the signoffs should be correct now." Fix up trivial conflicts in Documentation/feature-removal-schedule.txt arch/powerpc/kvm/book3s_segment.S and arch/x86/include/asm/kvm_para.h. I suspect the kvm_para.h resolution ends up doing the "do I have cpuid" check effectively twice (it was done differently in two different commits), but better safe than sorry ;) * 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (125 commits) KVM: make asm-generic/kvm_para.h have an ifdef __KERNEL__ block KVM: s390: onereg for timer related registers KVM: s390: epoch difference and TOD programmable field KVM: s390: KVM_GET/SET_ONEREG for s390 KVM: s390: add capability indicating COW support KVM: Fix mmu_reload() clash with nested vmx event injection KVM: MMU: Don't use RCU for lockless shadow walking KVM: VMX: Optimize %ds, %es reload KVM: VMX: Fix %ds/%es clobber KVM: x86 emulator: convert bsf/bsr instructions to emulate_2op_SrcV_nobyte() KVM: VMX: unlike vmcs on fail path KVM: PPC: Emulator: clean up SPR reads and writes KVM: PPC: Emulator: clean up instruction parsing kvm/powerpc: Add new ioctl to retreive server MMU infos kvm/book3s: Make kernel emulated H_PUT_TCE available for "PR" KVM KVM: PPC: bookehv: Fix r8/r13 storing in level exception handler KVM: PPC: Book3S: Enable IRQs during exit handling KVM: PPC: Fix PR KVM on POWER7 bare metal KVM: PPC: Fix stbux emulation KVM: PPC: bookehv: Use lwz/stw instead of PPC_LL/PPC_STL for 32-bit fields ...
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