From 4b6486659a7defef82ea51b276024b3aa357fefc Mon Sep 17 00:00:00 2001 From: Bruce Rogers Date: Fri, 20 Jul 2012 10:44:24 -0600 Subject: KVM: x86: apply kvmclock offset to guest wall clock time 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 Signed-off-by: Bruce Rogers Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/x86.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/x86/kvm/x86.c') diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 59b59508ff0..42bce48f692 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -925,6 +925,10 @@ static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock) */ getboottime(&boot); + if (kvm->arch.kvmclock_offset) { + struct timespec ts = ns_to_timespec(kvm->arch.kvmclock_offset); + boot = timespec_sub(boot, ts); + } wc.sec = boot.tv_sec; wc.nsec = boot.tv_nsec; wc.version = version; -- cgit v1.2.3-70-g09d2 From 439793d4b3c99e550daebd868bbd58967c93d0b3 Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Wed, 1 Aug 2012 17:01:42 +0300 Subject: KVM: x86: update KVM_SAVE_MSRS_BEGIN to correct value 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 Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity --- arch/x86/kvm/x86.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/kvm/x86.c') diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 42bce48f692..dce75b76031 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -806,7 +806,7 @@ EXPORT_SYMBOL_GPL(kvm_rdpmc); * kvm-specific. Those are put in the beginning of the list. */ -#define KVM_SAVE_MSRS_BEGIN 9 +#define KVM_SAVE_MSRS_BEGIN 10 static u32 msrs_to_save[] = { MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK, MSR_KVM_SYSTEM_TIME_NEW, MSR_KVM_WALL_CLOCK_NEW, -- cgit v1.2.3-70-g09d2 From 1d92128fe9e30c2340283361957a840f108e4abf Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Sun, 26 Aug 2012 18:00:29 +0300 Subject: KVM: x86: fix KVM_GET_MSR for PV EOI KVM_GET_MSR was missing support for PV EOI, which is needed for migration. Signed-off-by: Michael S. Tsirkin Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/x86.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/x86/kvm/x86.c') diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index dce75b76031..148ed666e31 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2000,6 +2000,9 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata) case MSR_KVM_STEAL_TIME: data = vcpu->arch.st.msr_val; break; + case MSR_KVM_PV_EOI_EN: + data = vcpu->arch.pv_eoi.msr_val; + break; case MSR_IA32_P5_MC_ADDR: case MSR_IA32_P5_MC_TYPE: case MSR_IA32_MCG_CAP: -- cgit v1.2.3-70-g09d2 From 4484141a94f4a5afea6ebc0b2abba0aa1b0ae9d1 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Fri, 7 Sep 2012 14:14:20 +0800 Subject: KVM: fix error paths for failed gfn_to_page() calls This bug was triggered: [ 4220.198458] BUG: unable to handle kernel paging request at fffffffffffffffe [ 4220.203907] IP: [] put_page+0xf/0x34 ...... [ 4220.237326] Call Trace: [ 4220.237361] [] kvm_arch_destroy_vm+0xf9/0x101 [kvm] [ 4220.237382] [] kvm_put_kvm+0xcc/0x127 [kvm] [ 4220.237401] [] kvm_vcpu_release+0x18/0x1c [kvm] [ 4220.237407] [] __fput+0x111/0x1ed [ 4220.237411] [] ____fput+0xe/0x10 [ 4220.237418] [] task_work_run+0x5d/0x88 [ 4220.237424] [] 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 Signed-off-by: Avi Kivity --- arch/x86/kvm/vmx.c | 19 ++++++++++++++++--- arch/x86/kvm/x86.c | 13 ++++++++++--- 2 files changed, 26 insertions(+), 6 deletions(-) (limited to 'arch/x86/kvm/x86.c') diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 002b4a566e2..b1eb202ee76 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3619,6 +3619,7 @@ static void seg_setup(int seg) static int alloc_apic_access_page(struct kvm *kvm) { + struct page *page; struct kvm_userspace_memory_region kvm_userspace_mem; int r = 0; @@ -3633,7 +3634,13 @@ static int alloc_apic_access_page(struct kvm *kvm) if (r) goto out; - kvm->arch.apic_access_page = gfn_to_page(kvm, 0xfee00); + page = gfn_to_page(kvm, 0xfee00); + if (is_error_page(page)) { + r = -EFAULT; + goto out; + } + + kvm->arch.apic_access_page = page; out: mutex_unlock(&kvm->slots_lock); return r; @@ -3641,6 +3648,7 @@ out: static int alloc_identity_pagetable(struct kvm *kvm) { + struct page *page; struct kvm_userspace_memory_region kvm_userspace_mem; int r = 0; @@ -3656,8 +3664,13 @@ static int alloc_identity_pagetable(struct kvm *kvm) if (r) goto out; - kvm->arch.ept_identity_pagetable = gfn_to_page(kvm, - kvm->arch.ept_identity_map_addr >> PAGE_SHIFT); + page = gfn_to_page(kvm, kvm->arch.ept_identity_map_addr >> PAGE_SHIFT); + if (is_error_page(page)) { + r = -EFAULT; + goto out; + } + + kvm->arch.ept_identity_pagetable = page; out: mutex_unlock(&kvm->slots_lock); return r; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 148ed666e31..2966c847d48 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5113,17 +5113,20 @@ static void post_kvm_run_save(struct kvm_vcpu *vcpu) !kvm_event_needs_reinjection(vcpu); } -static void vapic_enter(struct kvm_vcpu *vcpu) +static int vapic_enter(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; struct page *page; if (!apic || !apic->vapic_addr) - return; + return 0; page = gfn_to_page(vcpu->kvm, apic->vapic_addr >> PAGE_SHIFT); + if (is_error_page(page)) + return -EFAULT; vcpu->arch.apic->vapic_page = page; + return 0; } static void vapic_exit(struct kvm_vcpu *vcpu) @@ -5430,7 +5433,11 @@ static int __vcpu_run(struct kvm_vcpu *vcpu) } vcpu->srcu_idx = srcu_read_lock(&kvm->srcu); - vapic_enter(vcpu); + r = vapic_enter(vcpu); + if (r) { + srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx); + return r; + } r = 1; while (r > 0) { -- cgit v1.2.3-70-g09d2