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authorLinus Torvalds <torvalds@linux-foundation.org>2021-04-01 22:42:55 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-04-01 22:42:55 +0300
commit6905b1dc3c32a094f0da61bd656a740f0a97d592 (patch)
tree980c9c459b46dedf175a173f30582dee3cd29a14 /arch
parenta80314c327a937ff1213288adf0d11414c40a898 (diff)
parent55626ca9c6909d077eca71bccbe15fef6e5ad917 (diff)
downloadlinux-6905b1dc3c32a094f0da61bd656a740f0a97d592.tar.xz
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini: "It's a bit larger than I (and probably you) would like by the time we get to -rc6, but perhaps not entirely unexpected since the changes in the last merge window were larger than usual. x86: - Fixes for missing TLB flushes with TDP MMU - Fixes for race conditions in nested SVM - Fixes for lockdep splat with Xen emulation - Fix for kvmclock underflow - Fix srcdir != builddir builds - Other small cleanups ARM: - Fix GICv3 MMIO compatibility probing - Prevent guests from using the ARMv8.4 self-hosted tracing extension" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: selftests: kvm: Check that TSC page value is small after KVM_SET_CLOCK(0) KVM: x86: Prevent 'hv_clock->system_time' from going negative in kvm_guest_time_update() KVM: x86: disable interrupts while pvclock_gtod_sync_lock is taken KVM: x86: reduce pvclock_gtod_sync_lock critical sections KVM: SVM: ensure that EFER.SVME is set when running nested guest or on nested vmexit KVM: SVM: load control fields from VMCB12 before checking them KVM: x86/mmu: Don't allow TDP MMU to yield when recovering NX pages KVM: x86/mmu: Ensure TLBs are flushed for TDP MMU during NX zapping KVM: x86/mmu: Ensure TLBs are flushed when yielding during GFN range zap KVM: make: Fix out-of-source module builds selftests: kvm: make hardware_disable_test less verbose KVM: x86/vPMU: Forbid writing to MSR_F15H_PERF MSRs when guest doesn't have X86_FEATURE_PERFCTR_CORE KVM: x86: remove unused declaration of kvm_write_tsc() KVM: clean up the unused argument tools/kvm_stat: Add restart delay KVM: arm64: Fix CPU interface MMIO compatibility detection KVM: arm64: Disable guest access to trace filter controls KVM: arm64: Hide system instruction access to Trace registers
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/include/asm/kvm_arm.h1
-rw-r--r--arch/arm64/kernel/cpufeature.c1
-rw-r--r--arch/arm64/kvm/debug.c2
-rw-r--r--arch/arm64/kvm/hyp/vgic-v3-sr.c9
-rw-r--r--arch/x86/kvm/Makefile2
-rw-r--r--arch/x86/kvm/mmu/mmu.c9
-rw-r--r--arch/x86/kvm/mmu/tdp_mmu.c26
-rw-r--r--arch/x86/kvm/mmu/tdp_mmu.h24
-rw-r--r--arch/x86/kvm/svm/nested.c28
-rw-r--r--arch/x86/kvm/svm/pmu.c8
-rw-r--r--arch/x86/kvm/x86.c57
-rw-r--r--arch/x86/kvm/x86.h1
12 files changed, 122 insertions, 46 deletions
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 4e90c2debf70..94d4025acc0b 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -278,6 +278,7 @@
#define CPTR_EL2_DEFAULT CPTR_EL2_RES1
/* Hyp Debug Configuration Register bits */
+#define MDCR_EL2_TTRF (1 << 19)
#define MDCR_EL2_TPMS (1 << 14)
#define MDCR_EL2_E2PB_MASK (UL(0x3))
#define MDCR_EL2_E2PB_SHIFT (UL(12))
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 2a5d9854d664..e5281e1c8f1d 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -383,7 +383,6 @@ static const struct arm64_ftr_bits ftr_id_aa64dfr0[] = {
* of support.
*/
S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64DFR0_PMUVER_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_TRACEVER_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_DEBUGVER_SHIFT, 4, 0x6),
ARM64_FTR_END,
};
diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c
index 7a7e425616b5..dbc890511631 100644
--- a/arch/arm64/kvm/debug.c
+++ b/arch/arm64/kvm/debug.c
@@ -89,6 +89,7 @@ void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu)
* - Debug ROM Address (MDCR_EL2_TDRA)
* - OS related registers (MDCR_EL2_TDOSA)
* - Statistical profiler (MDCR_EL2_TPMS/MDCR_EL2_E2PB)
+ * - Self-hosted Trace Filter controls (MDCR_EL2_TTRF)
*
* Additionally, KVM only traps guest accesses to the debug registers if
* the guest is not actively using them (see the KVM_ARM64_DEBUG_DIRTY
@@ -112,6 +113,7 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu)
vcpu->arch.mdcr_el2 = __this_cpu_read(mdcr_el2) & MDCR_EL2_HPMN_MASK;
vcpu->arch.mdcr_el2 |= (MDCR_EL2_TPM |
MDCR_EL2_TPMS |
+ MDCR_EL2_TTRF |
MDCR_EL2_TPMCR |
MDCR_EL2_TDRA |
MDCR_EL2_TDOSA);
diff --git a/arch/arm64/kvm/hyp/vgic-v3-sr.c b/arch/arm64/kvm/hyp/vgic-v3-sr.c
index ee3682b9873c..39f8f7f9227c 100644
--- a/arch/arm64/kvm/hyp/vgic-v3-sr.c
+++ b/arch/arm64/kvm/hyp/vgic-v3-sr.c
@@ -429,6 +429,13 @@ u64 __vgic_v3_get_gic_config(void)
if (has_vhe())
flags = local_daif_save();
+ /*
+ * Table 11-2 "Permitted ICC_SRE_ELx.SRE settings" indicates
+ * that to be able to set ICC_SRE_EL1.SRE to 0, all the
+ * interrupt overrides must be set. You've got to love this.
+ */
+ sysreg_clear_set(hcr_el2, 0, HCR_AMO | HCR_FMO | HCR_IMO);
+ isb();
write_gicreg(0, ICC_SRE_EL1);
isb();
@@ -436,6 +443,8 @@ u64 __vgic_v3_get_gic_config(void)
write_gicreg(sre, ICC_SRE_EL1);
isb();
+ sysreg_clear_set(hcr_el2, HCR_AMO | HCR_FMO | HCR_IMO, 0);
+ isb();
if (has_vhe())
local_daif_restore(flags);
diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
index 1b4766fe1de2..eafc4d601f25 100644
--- a/arch/x86/kvm/Makefile
+++ b/arch/x86/kvm/Makefile
@@ -1,6 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
-ccflags-y += -Iarch/x86/kvm
+ccflags-y += -I $(srctree)/arch/x86/kvm
ccflags-$(CONFIG_KVM_WERROR) += -Werror
ifeq ($(CONFIG_FRAME_POINTER),y)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index d75524bc8423..486aa94ecf1d 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5884,6 +5884,7 @@ static void kvm_recover_nx_lpages(struct kvm *kvm)
struct kvm_mmu_page *sp;
unsigned int ratio;
LIST_HEAD(invalid_list);
+ bool flush = false;
ulong to_zap;
rcu_idx = srcu_read_lock(&kvm->srcu);
@@ -5905,19 +5906,19 @@ static void kvm_recover_nx_lpages(struct kvm *kvm)
lpage_disallowed_link);
WARN_ON_ONCE(!sp->lpage_disallowed);
if (is_tdp_mmu_page(sp)) {
- kvm_tdp_mmu_zap_gfn_range(kvm, sp->gfn,
- sp->gfn + KVM_PAGES_PER_HPAGE(sp->role.level));
+ flush = kvm_tdp_mmu_zap_sp(kvm, sp);
} else {
kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list);
WARN_ON_ONCE(sp->lpage_disallowed);
}
if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) {
- kvm_mmu_commit_zap_page(kvm, &invalid_list);
+ kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush);
cond_resched_rwlock_write(&kvm->mmu_lock);
+ flush = false;
}
}
- kvm_mmu_commit_zap_page(kvm, &invalid_list);
+ kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush);
write_unlock(&kvm->mmu_lock);
srcu_read_unlock(&kvm->srcu, rcu_idx);
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 462b1f71c77f..018d82e73e31 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -86,7 +86,7 @@ static inline struct kvm_mmu_page *tdp_mmu_next_root(struct kvm *kvm,
list_for_each_entry(_root, &_kvm->arch.tdp_mmu_roots, link)
static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
- gfn_t start, gfn_t end, bool can_yield);
+ gfn_t start, gfn_t end, bool can_yield, bool flush);
void kvm_tdp_mmu_free_root(struct kvm *kvm, struct kvm_mmu_page *root)
{
@@ -99,7 +99,7 @@ void kvm_tdp_mmu_free_root(struct kvm *kvm, struct kvm_mmu_page *root)
list_del(&root->link);
- zap_gfn_range(kvm, root, 0, max_gfn, false);
+ zap_gfn_range(kvm, root, 0, max_gfn, false, false);
free_page((unsigned long)root->spt);
kmem_cache_free(mmu_page_header_cache, root);
@@ -668,20 +668,21 @@ static inline bool tdp_mmu_iter_cond_resched(struct kvm *kvm,
* scheduler needs the CPU or there is contention on the MMU lock. If this
* function cannot yield, it will not release the MMU lock or reschedule and
* the caller must ensure it does not supply too large a GFN range, or the
- * operation can cause a soft lockup.
+ * operation can cause a soft lockup. Note, in some use cases a flush may be
+ * required by prior actions. Ensure the pending flush is performed prior to
+ * yielding.
*/
static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
- gfn_t start, gfn_t end, bool can_yield)
+ gfn_t start, gfn_t end, bool can_yield, bool flush)
{
struct tdp_iter iter;
- bool flush_needed = false;
rcu_read_lock();
tdp_root_for_each_pte(iter, root, start, end) {
if (can_yield &&
- tdp_mmu_iter_cond_resched(kvm, &iter, flush_needed)) {
- flush_needed = false;
+ tdp_mmu_iter_cond_resched(kvm, &iter, flush)) {
+ flush = false;
continue;
}
@@ -699,11 +700,11 @@ static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
continue;
tdp_mmu_set_spte(kvm, &iter, 0);
- flush_needed = true;
+ flush = true;
}
rcu_read_unlock();
- return flush_needed;
+ return flush;
}
/*
@@ -712,13 +713,14 @@ static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
* SPTEs have been cleared and a TLB flush is needed before releasing the
* MMU lock.
*/
-bool kvm_tdp_mmu_zap_gfn_range(struct kvm *kvm, gfn_t start, gfn_t end)
+bool __kvm_tdp_mmu_zap_gfn_range(struct kvm *kvm, gfn_t start, gfn_t end,
+ bool can_yield)
{
struct kvm_mmu_page *root;
bool flush = false;
for_each_tdp_mmu_root_yield_safe(kvm, root)
- flush |= zap_gfn_range(kvm, root, start, end, true);
+ flush = zap_gfn_range(kvm, root, start, end, can_yield, flush);
return flush;
}
@@ -930,7 +932,7 @@ static int zap_gfn_range_hva_wrapper(struct kvm *kvm,
struct kvm_mmu_page *root, gfn_t start,
gfn_t end, unsigned long unused)
{
- return zap_gfn_range(kvm, root, start, end, false);
+ return zap_gfn_range(kvm, root, start, end, false, false);
}
int kvm_tdp_mmu_zap_hva_range(struct kvm *kvm, unsigned long start,
diff --git a/arch/x86/kvm/mmu/tdp_mmu.h b/arch/x86/kvm/mmu/tdp_mmu.h
index 3b761c111bff..31096ece9b14 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.h
+++ b/arch/x86/kvm/mmu/tdp_mmu.h
@@ -8,7 +8,29 @@
hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu);
void kvm_tdp_mmu_free_root(struct kvm *kvm, struct kvm_mmu_page *root);
-bool kvm_tdp_mmu_zap_gfn_range(struct kvm *kvm, gfn_t start, gfn_t end);
+bool __kvm_tdp_mmu_zap_gfn_range(struct kvm *kvm, gfn_t start, gfn_t end,
+ bool can_yield);
+static inline bool kvm_tdp_mmu_zap_gfn_range(struct kvm *kvm, gfn_t start,
+ gfn_t end)
+{
+ return __kvm_tdp_mmu_zap_gfn_range(kvm, start, end, true);
+}
+static inline bool kvm_tdp_mmu_zap_sp(struct kvm *kvm, struct kvm_mmu_page *sp)
+{
+ gfn_t end = sp->gfn + KVM_PAGES_PER_HPAGE(sp->role.level);
+
+ /*
+ * Don't allow yielding, as the caller may have a flush pending. Note,
+ * if mmu_lock is held for write, zapping will never yield in this case,
+ * but explicitly disallow it for safety. The TDP MMU does not yield
+ * until it has made forward progress (steps sideways), and when zapping
+ * a single shadow page that it's guaranteed to see (thus the mmu_lock
+ * requirement), its "step sideways" will always step beyond the bounds
+ * of the shadow page's gfn range and stop iterating before yielding.
+ */
+ lockdep_assert_held_write(&kvm->mmu_lock);
+ return __kvm_tdp_mmu_zap_gfn_range(kvm, sp->gfn, end, false);
+}
void kvm_tdp_mmu_zap_all(struct kvm *kvm);
int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 35891d9a1099..fb204eaa8bb3 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -246,11 +246,18 @@ static bool nested_vmcb_check_controls(struct vmcb_control_area *control)
return true;
}
-static bool nested_vmcb_checks(struct vcpu_svm *svm, struct vmcb *vmcb12)
+static bool nested_vmcb_check_save(struct vcpu_svm *svm, struct vmcb *vmcb12)
{
struct kvm_vcpu *vcpu = &svm->vcpu;
bool vmcb12_lma;
+ /*
+ * FIXME: these should be done after copying the fields,
+ * to avoid TOC/TOU races. For these save area checks
+ * the possible damage is limited since kvm_set_cr0 and
+ * kvm_set_cr4 handle failure; EFER_SVME is an exception
+ * so it is force-set later in nested_prepare_vmcb_save.
+ */
if ((vmcb12->save.efer & EFER_SVME) == 0)
return false;
@@ -271,7 +278,7 @@ static bool nested_vmcb_checks(struct vcpu_svm *svm, struct vmcb *vmcb12)
if (!kvm_is_valid_cr4(&svm->vcpu, vmcb12->save.cr4))
return false;
- return nested_vmcb_check_controls(&vmcb12->control);
+ return true;
}
static void load_nested_vmcb_control(struct vcpu_svm *svm,
@@ -396,7 +403,14 @@ static void nested_prepare_vmcb_save(struct vcpu_svm *svm, struct vmcb *vmcb12)
svm->vmcb->save.gdtr = vmcb12->save.gdtr;
svm->vmcb->save.idtr = vmcb12->save.idtr;
kvm_set_rflags(&svm->vcpu, vmcb12->save.rflags | X86_EFLAGS_FIXED);
- svm_set_efer(&svm->vcpu, vmcb12->save.efer);
+
+ /*
+ * Force-set EFER_SVME even though it is checked earlier on the
+ * VMCB12, because the guest can flip the bit between the check
+ * and now. Clearing EFER_SVME would call svm_free_nested.
+ */
+ svm_set_efer(&svm->vcpu, vmcb12->save.efer | EFER_SVME);
+
svm_set_cr0(&svm->vcpu, vmcb12->save.cr0);
svm_set_cr4(&svm->vcpu, vmcb12->save.cr4);
svm->vmcb->save.cr2 = svm->vcpu.arch.cr2 = vmcb12->save.cr2;
@@ -468,7 +482,6 @@ int enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb12_gpa,
svm->nested.vmcb12_gpa = vmcb12_gpa;
- load_nested_vmcb_control(svm, &vmcb12->control);
nested_prepare_vmcb_control(svm);
nested_prepare_vmcb_save(svm, vmcb12);
@@ -515,7 +528,10 @@ int nested_svm_vmrun(struct vcpu_svm *svm)
if (WARN_ON_ONCE(!svm->nested.initialized))
return -EINVAL;
- if (!nested_vmcb_checks(svm, vmcb12)) {
+ load_nested_vmcb_control(svm, &vmcb12->control);
+
+ if (!nested_vmcb_check_save(svm, vmcb12) ||
+ !nested_vmcb_check_controls(&svm->nested.ctl)) {
vmcb12->control.exit_code = SVM_EXIT_ERR;
vmcb12->control.exit_code_hi = 0;
vmcb12->control.exit_info_1 = 0;
@@ -1209,6 +1225,8 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
*/
if (!(save->cr0 & X86_CR0_PG))
goto out_free;
+ if (!(save->efer & EFER_SVME))
+ goto out_free;
/*
* All checks done, we can enter guest mode. L1 control fields
diff --git a/arch/x86/kvm/svm/pmu.c b/arch/x86/kvm/svm/pmu.c
index 035da07500e8..fdf587f19c5f 100644
--- a/arch/x86/kvm/svm/pmu.c
+++ b/arch/x86/kvm/svm/pmu.c
@@ -98,6 +98,8 @@ static enum index msr_to_index(u32 msr)
static inline struct kvm_pmc *get_gp_pmc_amd(struct kvm_pmu *pmu, u32 msr,
enum pmu_type type)
{
+ struct kvm_vcpu *vcpu = pmu_to_vcpu(pmu);
+
switch (msr) {
case MSR_F15H_PERF_CTL0:
case MSR_F15H_PERF_CTL1:
@@ -105,6 +107,9 @@ static inline struct kvm_pmc *get_gp_pmc_amd(struct kvm_pmu *pmu, u32 msr,
case MSR_F15H_PERF_CTL3:
case MSR_F15H_PERF_CTL4:
case MSR_F15H_PERF_CTL5:
+ if (!guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE))
+ return NULL;
+ fallthrough;
case MSR_K7_EVNTSEL0 ... MSR_K7_EVNTSEL3:
if (type != PMU_TYPE_EVNTSEL)
return NULL;
@@ -115,6 +120,9 @@ static inline struct kvm_pmc *get_gp_pmc_amd(struct kvm_pmu *pmu, u32 msr,
case MSR_F15H_PERF_CTR3:
case MSR_F15H_PERF_CTR4:
case MSR_F15H_PERF_CTR5:
+ if (!guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE))
+ return NULL;
+ fallthrough;
case MSR_K7_PERFCTR0 ... MSR_K7_PERFCTR3:
if (type != PMU_TYPE_COUNTER)
return NULL;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index fe806e894212..eca63625aee4 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -271,8 +271,7 @@ static struct kmem_cache *x86_emulator_cache;
* When called, it means the previous get/set msr reached an invalid msr.
* Return true if we want to ignore/silent this failed msr access.
*/
-static bool kvm_msr_ignored_check(struct kvm_vcpu *vcpu, u32 msr,
- u64 data, bool write)
+static bool kvm_msr_ignored_check(u32 msr, u64 data, bool write)
{
const char *op = write ? "wrmsr" : "rdmsr";
@@ -1445,7 +1444,7 @@ static int do_get_msr_feature(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
if (r == KVM_MSR_RET_INVALID) {
/* Unconditionally clear the output for simplicity */
*data = 0;
- if (kvm_msr_ignored_check(vcpu, index, 0, false))
+ if (kvm_msr_ignored_check(index, 0, false))
r = 0;
}
@@ -1620,7 +1619,7 @@ static int kvm_set_msr_ignored_check(struct kvm_vcpu *vcpu,
int ret = __kvm_set_msr(vcpu, index, data, host_initiated);
if (ret == KVM_MSR_RET_INVALID)
- if (kvm_msr_ignored_check(vcpu, index, data, true))
+ if (kvm_msr_ignored_check(index, data, true))
ret = 0;
return ret;
@@ -1658,7 +1657,7 @@ static int kvm_get_msr_ignored_check(struct kvm_vcpu *vcpu,
if (ret == KVM_MSR_RET_INVALID) {
/* Unconditionally clear *data for simplicity */
*data = 0;
- if (kvm_msr_ignored_check(vcpu, index, 0, false))
+ if (kvm_msr_ignored_check(index, 0, false))
ret = 0;
}
@@ -2329,7 +2328,7 @@ static void kvm_synchronize_tsc(struct kvm_vcpu *vcpu, u64 data)
kvm_vcpu_write_tsc_offset(vcpu, offset);
raw_spin_unlock_irqrestore(&kvm->arch.tsc_write_lock, flags);
- spin_lock(&kvm->arch.pvclock_gtod_sync_lock);
+ spin_lock_irqsave(&kvm->arch.pvclock_gtod_sync_lock, flags);
if (!matched) {
kvm->arch.nr_vcpus_matched_tsc = 0;
} else if (!already_matched) {
@@ -2337,7 +2336,7 @@ static void kvm_synchronize_tsc(struct kvm_vcpu *vcpu, u64 data)
}
kvm_track_tsc_matching(vcpu);
- spin_unlock(&kvm->arch.pvclock_gtod_sync_lock);
+ spin_unlock_irqrestore(&kvm->arch.pvclock_gtod_sync_lock, flags);
}
static inline void adjust_tsc_offset_guest(struct kvm_vcpu *vcpu,
@@ -2559,13 +2558,16 @@ static void kvm_gen_update_masterclock(struct kvm *kvm)
int i;
struct kvm_vcpu *vcpu;
struct kvm_arch *ka = &kvm->arch;
+ unsigned long flags;
kvm_hv_invalidate_tsc_page(kvm);
- spin_lock(&ka->pvclock_gtod_sync_lock);
kvm_make_mclock_inprogress_request(kvm);
+
/* no guest entries from this point */
+ spin_lock_irqsave(&ka->pvclock_gtod_sync_lock, flags);
pvclock_update_vm_gtod_copy(kvm);
+ spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags);
kvm_for_each_vcpu(i, vcpu, kvm)
kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
@@ -2573,8 +2575,6 @@ static void kvm_gen_update_masterclock(struct kvm *kvm)
/* guest entries allowed */
kvm_for_each_vcpu(i, vcpu, kvm)
kvm_clear_request(KVM_REQ_MCLOCK_INPROGRESS, vcpu);
-
- spin_unlock(&ka->pvclock_gtod_sync_lock);
#endif
}
@@ -2582,17 +2582,18 @@ u64 get_kvmclock_ns(struct kvm *kvm)
{
struct kvm_arch *ka = &kvm->arch;
struct pvclock_vcpu_time_info hv_clock;
+ unsigned long flags;
u64 ret;
- spin_lock(&ka->pvclock_gtod_sync_lock);
+ spin_lock_irqsave(&ka->pvclock_gtod_sync_lock, flags);
if (!ka->use_master_clock) {
- spin_unlock(&ka->pvclock_gtod_sync_lock);
+ spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags);
return get_kvmclock_base_ns() + ka->kvmclock_offset;
}
hv_clock.tsc_timestamp = ka->master_cycle_now;
hv_clock.system_time = ka->master_kernel_ns + ka->kvmclock_offset;
- spin_unlock(&ka->pvclock_gtod_sync_lock);
+ spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags);
/* both __this_cpu_read() and rdtsc() should be on the same cpu */
get_cpu();
@@ -2686,13 +2687,13 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
* If the host uses TSC clock, then passthrough TSC as stable
* to the guest.
*/
- spin_lock(&ka->pvclock_gtod_sync_lock);
+ spin_lock_irqsave(&ka->pvclock_gtod_sync_lock, flags);
use_master_clock = ka->use_master_clock;
if (use_master_clock) {
host_tsc = ka->master_cycle_now;
kernel_ns = ka->master_kernel_ns;
}
- spin_unlock(&ka->pvclock_gtod_sync_lock);
+ spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags);
/* Keep irq disabled to prevent changes to the clock */
local_irq_save(flags);
@@ -5726,6 +5727,7 @@ set_pit2_out:
}
#endif
case KVM_SET_CLOCK: {
+ struct kvm_arch *ka = &kvm->arch;
struct kvm_clock_data user_ns;
u64 now_ns;
@@ -5744,8 +5746,22 @@ set_pit2_out:
* pvclock_update_vm_gtod_copy().
*/
kvm_gen_update_masterclock(kvm);
- now_ns = get_kvmclock_ns(kvm);
- kvm->arch.kvmclock_offset += user_ns.clock - now_ns;
+
+ /*
+ * This pairs with kvm_guest_time_update(): when masterclock is
+ * in use, we use master_kernel_ns + kvmclock_offset to set
+ * unsigned 'system_time' so if we use get_kvmclock_ns() (which
+ * is slightly ahead) here we risk going negative on unsigned
+ * 'system_time' when 'user_ns.clock' is very small.
+ */
+ spin_lock_irq(&ka->pvclock_gtod_sync_lock);
+ if (kvm->arch.use_master_clock)
+ now_ns = ka->master_kernel_ns;
+ else
+ now_ns = get_kvmclock_base_ns();
+ ka->kvmclock_offset = user_ns.clock - now_ns;
+ spin_unlock_irq(&ka->pvclock_gtod_sync_lock);
+
kvm_make_all_cpus_request(kvm, KVM_REQ_CLOCK_UPDATE);
break;
}
@@ -7724,6 +7740,7 @@ static void kvm_hyperv_tsc_notifier(void)
struct kvm *kvm;
struct kvm_vcpu *vcpu;
int cpu;
+ unsigned long flags;
mutex_lock(&kvm_lock);
list_for_each_entry(kvm, &vm_list, vm_list)
@@ -7739,17 +7756,15 @@ static void kvm_hyperv_tsc_notifier(void)
list_for_each_entry(kvm, &vm_list, vm_list) {
struct kvm_arch *ka = &kvm->arch;
- spin_lock(&ka->pvclock_gtod_sync_lock);
-
+ spin_lock_irqsave(&ka->pvclock_gtod_sync_lock, flags);
pvclock_update_vm_gtod_copy(kvm);
+ spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags);
kvm_for_each_vcpu(cpu, vcpu, kvm)
kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
kvm_for_each_vcpu(cpu, vcpu, kvm)
kvm_clear_request(KVM_REQ_MCLOCK_INPROGRESS, vcpu);
-
- spin_unlock(&ka->pvclock_gtod_sync_lock);
}
mutex_unlock(&kvm_lock);
}
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 39eb04887141..9035e34aa156 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -250,7 +250,6 @@ static inline bool kvm_vcpu_latch_init(struct kvm_vcpu *vcpu)
void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock, int sec_hi_ofs);
void kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip);
-void kvm_write_tsc(struct kvm_vcpu *vcpu, struct msr_data *msr);
u64 get_kvmclock_ns(struct kvm *kvm);
int kvm_read_guest_virt(struct kvm_vcpu *vcpu,