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2013-01-08KVM: x86: use dynamic percpu allocations for shared msrs areaMarcelo Tosatti
Use dynamic percpu allocations for the shared msrs structure, to avoid using the limited reserved percpu space. Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-12-13Merge tag 'kvm-3.8-1' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Marcelo Tosatti: "Considerable KVM/PPC work, x86 kvmclock vsyscall support, IA32_TSC_ADJUST MSR emulation, amongst others." Fix up trivial conflict in kernel/sched/core.c due to cross-cpu migration notifier added next to rq migration call-back. * tag 'kvm-3.8-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (156 commits) KVM: emulator: fix real mode segment checks in address linearization VMX: remove unneeded enable_unrestricted_guest check KVM: VMX: fix DPL during entry to protected mode x86/kexec: crash_vmclear_local_vmcss needs __rcu kvm: Fix irqfd resampler list walk KVM: VMX: provide the vmclear function and a bitmap to support VMCLEAR in kdump x86/kexec: VMCLEAR VMCSs loaded on all cpus if necessary KVM: MMU: optimize for set_spte KVM: PPC: booke: Get/set guest EPCR register using ONE_REG interface KVM: PPC: bookehv: Add EPCR support in mtspr/mfspr emulation KVM: PPC: bookehv: Add guest computation mode for irq delivery KVM: PPC: Make EPCR a valid field for booke64 and bookehv KVM: PPC: booke: Extend MAS2 EPN mask for 64-bit KVM: PPC: e500: Mask MAS2 EPN high 32-bits in 32/64 tlbwe emulation KVM: PPC: Mask ea's high 32-bits in 32/64 instr emulation KVM: PPC: e500: Add emulation helper for getting instruction ea KVM: PPC: bookehv64: Add support for interrupt handling KVM: PPC: bookehv: Remove GET_VCPU macro from exception handler KVM: PPC: booke: Fix get_tb() compile error on 64-bit KVM: PPC: e500: Silence bogus GCC warning in tlb code ...
2012-12-05KVM: x86: Make register state after reset conform to specificationJulian Stecklina
VMX behaves now as SVM wrt to FPU initialization. Code has been moved to generic code path. General-purpose registers are now cleared on reset and INIT. SVM code properly initializes EDX. Signed-off-by: Julian Stecklina <jsteckli@os.inf.tu-dresden.de> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2012-12-02KVM: x86: Fix uninitialized return codeJan Kiszka
This is a regression caused by 18595411a7. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2012-11-30KVM: x86: Emulate IA32_TSC_ADJUST MSRWill Auld
CPUID.7.0.EBX[1]=1 indicates IA32_TSC_ADJUST MSR 0x3b is supported Basic design is to emulate the MSR by allowing reads and writes to a guest vcpu specific location to store the value of the emulated MSR while adding the value to the vmcs tsc_offset. In this way the IA32_TSC_ADJUST value will be included in all reads to the TSC MSR whether through rdmsr or rdtsc. This is of course as long as the "use TSC counter offsetting" VM-execution control is enabled as well as the IA32_TSC_ADJUST control. However, because hardware will only return the TSC + IA32_TSC_ADJUST + vmsc tsc_offset for a guest process when it does and rdtsc (with the correct settings) the value of our virtualized IA32_TSC_ADJUST must be stored in one of these three locations. The argument against storing it in the actual MSR is performance. This is likely to be seldom used while the save/restore is required on every transition. IA32_TSC_ADJUST was created as a way to solve some issues with writing TSC itself so that is not an option either. The remaining option, defined above as our solution has the problem of returning incorrect vmcs tsc_offset values (unless we intercept and fix, not done here) as mentioned above. However, more problematic is that storing the data in vmcs tsc_offset will have a different semantic effect on the system than does using the actual MSR. This is illustrated in the following example: The hypervisor set the IA32_TSC_ADJUST, then the guest sets it and a guest process performs a rdtsc. In this case the guest process will get TSC + IA32_TSC_ADJUST_hyperviser + vmsc tsc_offset including IA32_TSC_ADJUST_guest. While the total system semantics changed the semantics as seen by the guest do not and hence this will not cause a problem. Signed-off-by: Will Auld <will.auld@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-30KVM: x86: Add code to track call origin for msr assignmentWill Auld
In order to track who initiated the call (host or guest) to modify an msr value I have changed function call parameters along the call path. The specific change is to add a struct pointer parameter that points to (index, data, caller) information rather than having this information passed as individual parameters. The initial use for this capability is for updating the IA32_TSC_ADJUST msr while setting the tsc value. It is anticipated that this capability is useful for other tasks. Signed-off-by: Will Auld <will.auld@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-27KVM: x86: update pvclock area conditionally, on cpu migrationMarcelo Tosatti
As requested by Glauber, do not update kvmclock area on vcpu->pcpu migration, in case the host has stable TSC. This is to reduce cacheline bouncing. Acked-by: Glauber Costa <glommer@parallels.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-27KVM: x86: require matched TSC offsets for master clockMarcelo Tosatti
With master clock, a pvclock clock read calculates: ret = system_timestamp + [ (rdtsc + tsc_offset) - tsc_timestamp ] Where 'rdtsc' is the host TSC. system_timestamp and tsc_timestamp are unique, one tuple per VM: the "master clock". Given a host with synchronized TSCs, its obvious that guest TSC must be matched for the above to guarantee monotonicity. Allow master clock usage only if guest TSCs are synchronized. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-27KVM: x86: add kvm_arch_vcpu_postcreate callback, move TSC initializationMarcelo Tosatti
TSC initialization will soon make use of online_vcpus. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-27KVM: x86: implement PVCLOCK_TSC_STABLE_BIT pvclock flagMarcelo Tosatti
KVM added a global variable to guarantee monotonicity in the guest. One of the reasons for that is that the time between 1. ktime_get_ts(&timespec); 2. rdtscll(tsc); Is variable. That is, given a host with stable TSC, suppose that two VCPUs read the same time via ktime_get_ts() above. The time required to execute 2. is not the same on those two instances executing in different VCPUS (cache misses, interrupts...). If the TSC value that is used by the host to interpolate when calculating the monotonic time is the same value used to calculate the tsc_timestamp value stored in the pvclock data structure, and a single <system_timestamp, tsc_timestamp> tuple is visible to all vcpus simultaneously, this problem disappears. See comment on top of pvclock_update_vm_gtod_copy for details. Monotonicity is then guaranteed by synchronicity of the host TSCs and guest TSCs. Set TSC stable pvclock flag in that case, allowing the guest to read clock from userspace. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-27KVM: x86: notifier for clocksource changesMarcelo Tosatti
Register a notifier for clocksource change event. In case the host switches to clock other than TSC, disable master clock usage. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-27KVM: x86: pass host_tsc to read_l1_tscMarcelo Tosatti
Allow the caller to pass host tsc value to kvm_x86_ops->read_l1_tsc(). Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-27KVM: x86: retain pvclock guest stopped bit in guest memoryMarcelo Tosatti
Otherwise its possible for an unrelated KVM_REQ_UPDATE_CLOCK (such as due to CPU migration) to clear the bit. Noticed by Paolo Bonzini. Reviewed-by: Gleb Natapov <gleb@redhat.com> Reviewed-by: Glauber Costa <glommer@parallels.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-13KVM: remove unnecessary return value checkGuo Chao
No need to check return value before breaking switch. Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-13KVM: x86: fix return value of kvm_vm_ioctl_set_tss_addr()Guo Chao
Return value of this function will be that of ioctl(). #include <stdio.h> #include <linux/kvm.h> int main () { int fd; fd = open ("/dev/kvm", 0); fd = ioctl (fd, KVM_CREATE_VM, 0); ioctl (fd, KVM_SET_TSS_ADDR, 0xfffff000); perror (""); return 0; } Output is "Operation not permitted". That's not what we want. Return -EINVAL in this case. Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-13KVM: do not kfree error pointerGuo Chao
We should avoid kfree()ing error pointer in kvm_vcpu_ioctl() and kvm_arch_vcpu_ioctl(). Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
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>
2012-10-29KVM: do not treat noslot pfn as a error pfnXiao Guangrong
This patch filters noslot pfn out from error pfns based on Marcelo comment: noslot pfn is not a error pfn After this patch, - is_noslot_pfn indicates that the gfn is not in slot - is_error_pfn indicates that the gfn is in slot but the error is occurred when translate the gfn to pfn - is_error_noslot_pfn indicates that the pfn either it is error pfns or it is noslot pfn And is_invalid_pfn can be removed, it makes the code more clean Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-10-18KVM: do not de-cache cr4 bits needlesslyGleb Natapov
Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-10-08KVM: x86: Make emulator_fix_hypercall staticJan Kiszka
No users outside of kvm/x86.c. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-10-08KVM: x86: Convert kvm_arch_vcpu_reset into private kvm_vcpu_resetJan Kiszka
There are no external callers of this function as there is no concept of resetting a vcpu from generic code. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.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>