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authorPaolo Bonzini <pbonzini@redhat.com>2022-12-06 12:29:06 -0500
committerPaolo Bonzini <pbonzini@redhat.com>2022-12-12 15:54:07 -0500
commit9352e7470a1b4edd2fa9d235420ecc7bc3971bdc (patch)
tree141ccdb777f2ee36764f2067ab43f23da114e08a /virt
parent2afc1fbbdab2aee831561f09f859989dcd5ed648 (diff)
parent5656374b168c98377b6feee8d7500993eebda230 (diff)
downloadlwn-9352e7470a1b4edd2fa9d235420ecc7bc3971bdc.tar.gz
lwn-9352e7470a1b4edd2fa9d235420ecc7bc3971bdc.zip
Merge remote-tracking branch 'kvm/queue' into HEAD
x86 Xen-for-KVM: * Allow the Xen runstate information to cross a page boundary * Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured * add support for 32-bit guests in SCHEDOP_poll x86 fixes: * One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0). * Reinstate IBPB on emulated VM-Exit that was incorrectly dropped a few years back when eliminating unnecessary barriers when switching between vmcs01 and vmcs02. * Clean up the MSR filter docs. * Clean up vmread_error_trampoline() to make it more obvious that params must be passed on the stack, even for x86-64. * Let userspace set all supported bits in MSR_IA32_FEAT_CTL irrespective of the current guest CPUID. * Fudge around a race with TSC refinement that results in KVM incorrectly thinking a guest needs TSC scaling when running on a CPU with a constant TSC, but no hardware-enumerated TSC frequency. * Advertise (on AMD) that the SMM_CTL MSR is not supported * Remove unnecessary exports Selftests: * Fix an inverted check in the access tracking perf test, and restore support for asserting that there aren't too many idle pages when running on bare metal. * Fix an ordering issue in the AMX test introduced by recent conversions to use kvm_cpu_has(), and harden the code to guard against similar bugs in the future. Anything that tiggers caching of KVM's supported CPUID, kvm_cpu_has() in this case, effectively hides opt-in XSAVE features if the caching occurs before the test opts in via prctl(). * Fix build errors that occur in certain setups (unsure exactly what is unique about the problematic setup) due to glibc overriding static_assert() to a variant that requires a custom message. * Introduce actual atomics for clear/set_bit() in selftests Documentation: * Remove deleted ioctls from documentation * Various fixes
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/kvm_main.c4
-rw-r--r--virt/kvm/pfncache.c112
2 files changed, 54 insertions, 62 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 3ee537eb0bab..954ab969f55e 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3519,10 +3519,6 @@ void kvm_vcpu_halt(struct kvm_vcpu *vcpu)
ktime_t stop = ktime_add_ns(start, vcpu->halt_poll_ns);
do {
- /*
- * This sets KVM_REQ_UNHALT if an interrupt
- * arrives.
- */
if (kvm_vcpu_check_block(vcpu) < 0)
goto out;
cpu_relax();
diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c
index 5f83321bfd2a..2d6aba677830 100644
--- a/virt/kvm/pfncache.c
+++ b/virt/kvm/pfncache.c
@@ -76,19 +76,17 @@ void gfn_to_pfn_cache_invalidate_start(struct kvm *kvm, unsigned long start,
}
}
-bool kvm_gfn_to_pfn_cache_check(struct kvm *kvm, struct gfn_to_pfn_cache *gpc,
- gpa_t gpa, unsigned long len)
+bool kvm_gpc_check(struct gfn_to_pfn_cache *gpc, unsigned long len)
{
- struct kvm_memslots *slots = kvm_memslots(kvm);
+ struct kvm_memslots *slots = kvm_memslots(gpc->kvm);
if (!gpc->active)
return false;
- if ((gpa & ~PAGE_MASK) + len > PAGE_SIZE)
+ if ((gpc->gpa & ~PAGE_MASK) + len > PAGE_SIZE)
return false;
- if (gpc->gpa != gpa || gpc->generation != slots->generation ||
- kvm_is_error_hva(gpc->uhva))
+ if (gpc->generation != slots->generation || kvm_is_error_hva(gpc->uhva))
return false;
if (!gpc->valid)
@@ -96,9 +94,9 @@ bool kvm_gfn_to_pfn_cache_check(struct kvm *kvm, struct gfn_to_pfn_cache *gpc,
return true;
}
-EXPORT_SYMBOL_GPL(kvm_gfn_to_pfn_cache_check);
+EXPORT_SYMBOL_GPL(kvm_gpc_check);
-static void gpc_unmap_khva(struct kvm *kvm, kvm_pfn_t pfn, void *khva)
+static void gpc_unmap_khva(kvm_pfn_t pfn, void *khva)
{
/* Unmap the old pfn/page if it was mapped before. */
if (!is_error_noslot_pfn(pfn) && khva) {
@@ -139,7 +137,7 @@ static inline bool mmu_notifier_retry_cache(struct kvm *kvm, unsigned long mmu_s
return kvm->mmu_invalidate_seq != mmu_seq;
}
-static kvm_pfn_t hva_to_pfn_retry(struct kvm *kvm, struct gfn_to_pfn_cache *gpc)
+static kvm_pfn_t hva_to_pfn_retry(struct gfn_to_pfn_cache *gpc)
{
/* Note, the new page offset may be different than the old! */
void *old_khva = gpc->khva - offset_in_page(gpc->khva);
@@ -159,7 +157,7 @@ static kvm_pfn_t hva_to_pfn_retry(struct kvm *kvm, struct gfn_to_pfn_cache *gpc)
gpc->valid = false;
do {
- mmu_seq = kvm->mmu_invalidate_seq;
+ mmu_seq = gpc->kvm->mmu_invalidate_seq;
smp_rmb();
write_unlock_irq(&gpc->lock);
@@ -177,7 +175,7 @@ static kvm_pfn_t hva_to_pfn_retry(struct kvm *kvm, struct gfn_to_pfn_cache *gpc)
* the existing mapping and didn't create a new one.
*/
if (new_khva != old_khva)
- gpc_unmap_khva(kvm, new_pfn, new_khva);
+ gpc_unmap_khva(new_pfn, new_khva);
kvm_release_pfn_clean(new_pfn);
@@ -217,7 +215,7 @@ static kvm_pfn_t hva_to_pfn_retry(struct kvm *kvm, struct gfn_to_pfn_cache *gpc)
* attempting to refresh.
*/
WARN_ON_ONCE(gpc->valid);
- } while (mmu_notifier_retry_cache(kvm, mmu_seq));
+ } while (mmu_notifier_retry_cache(gpc->kvm, mmu_seq));
gpc->valid = true;
gpc->pfn = new_pfn;
@@ -238,10 +236,10 @@ out_error:
return -EFAULT;
}
-int kvm_gfn_to_pfn_cache_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc,
- gpa_t gpa, unsigned long len)
+static int __kvm_gpc_refresh(struct gfn_to_pfn_cache *gpc, gpa_t gpa,
+ unsigned long len)
{
- struct kvm_memslots *slots = kvm_memslots(kvm);
+ struct kvm_memslots *slots = kvm_memslots(gpc->kvm);
unsigned long page_offset = gpa & ~PAGE_MASK;
bool unmap_old = false;
unsigned long old_uhva;
@@ -295,7 +293,7 @@ int kvm_gfn_to_pfn_cache_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc,
* drop the lock and do the HVA to PFN lookup again.
*/
if (!gpc->valid || old_uhva != gpc->uhva) {
- ret = hva_to_pfn_retry(kvm, gpc);
+ ret = hva_to_pfn_retry(gpc);
} else {
/*
* If the HVA→PFN mapping was already valid, don't unmap it.
@@ -303,9 +301,8 @@ int kvm_gfn_to_pfn_cache_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc,
* may have changed.
*/
gpc->khva = old_khva + page_offset;
- old_pfn = KVM_PFN_ERR_FAULT;
- old_khva = NULL;
ret = 0;
+ goto out_unlock;
}
out:
@@ -329,59 +326,41 @@ out_unlock:
mutex_unlock(&gpc->refresh_lock);
if (unmap_old)
- gpc_unmap_khva(kvm, old_pfn, old_khva);
+ gpc_unmap_khva(old_pfn, old_khva);
return ret;
}
-EXPORT_SYMBOL_GPL(kvm_gfn_to_pfn_cache_refresh);
-void kvm_gfn_to_pfn_cache_unmap(struct kvm *kvm, struct gfn_to_pfn_cache *gpc)
+int kvm_gpc_refresh(struct gfn_to_pfn_cache *gpc, unsigned long len)
{
- void *old_khva;
- kvm_pfn_t old_pfn;
-
- mutex_lock(&gpc->refresh_lock);
- write_lock_irq(&gpc->lock);
-
- gpc->valid = false;
-
- old_khva = gpc->khva - offset_in_page(gpc->khva);
- old_pfn = gpc->pfn;
-
- /*
- * We can leave the GPA → uHVA map cache intact but the PFN
- * lookup will need to be redone even for the same page.
- */
- gpc->khva = NULL;
- gpc->pfn = KVM_PFN_ERR_FAULT;
-
- write_unlock_irq(&gpc->lock);
- mutex_unlock(&gpc->refresh_lock);
-
- gpc_unmap_khva(kvm, old_pfn, old_khva);
+ return __kvm_gpc_refresh(gpc, gpc->gpa, len);
}
-EXPORT_SYMBOL_GPL(kvm_gfn_to_pfn_cache_unmap);
+EXPORT_SYMBOL_GPL(kvm_gpc_refresh);
-void kvm_gpc_init(struct gfn_to_pfn_cache *gpc)
+void kvm_gpc_init(struct gfn_to_pfn_cache *gpc, struct kvm *kvm,
+ struct kvm_vcpu *vcpu, enum pfn_cache_usage usage)
{
+ WARN_ON_ONCE(!usage || (usage & KVM_GUEST_AND_HOST_USE_PFN) != usage);
+ WARN_ON_ONCE((usage & KVM_GUEST_USES_PFN) && !vcpu);
+
rwlock_init(&gpc->lock);
mutex_init(&gpc->refresh_lock);
+
+ gpc->kvm = kvm;
+ gpc->vcpu = vcpu;
+ gpc->usage = usage;
+ gpc->pfn = KVM_PFN_ERR_FAULT;
+ gpc->uhva = KVM_HVA_ERR_BAD;
}
EXPORT_SYMBOL_GPL(kvm_gpc_init);
-int kvm_gpc_activate(struct kvm *kvm, struct gfn_to_pfn_cache *gpc,
- struct kvm_vcpu *vcpu, enum pfn_cache_usage usage,
- gpa_t gpa, unsigned long len)
+int kvm_gpc_activate(struct gfn_to_pfn_cache *gpc, gpa_t gpa, unsigned long len)
{
- WARN_ON_ONCE(!usage || (usage & KVM_GUEST_AND_HOST_USE_PFN) != usage);
+ struct kvm *kvm = gpc->kvm;
if (!gpc->active) {
- gpc->khva = NULL;
- gpc->pfn = KVM_PFN_ERR_FAULT;
- gpc->uhva = KVM_HVA_ERR_BAD;
- gpc->vcpu = vcpu;
- gpc->usage = usage;
- gpc->valid = false;
+ if (KVM_BUG_ON(gpc->valid, kvm))
+ return -EIO;
spin_lock(&kvm->gpc_lock);
list_add(&gpc->list, &kvm->gpc_list);
@@ -396,12 +375,16 @@ int kvm_gpc_activate(struct kvm *kvm, struct gfn_to_pfn_cache *gpc,
gpc->active = true;
write_unlock_irq(&gpc->lock);
}
- return kvm_gfn_to_pfn_cache_refresh(kvm, gpc, gpa, len);
+ return __kvm_gpc_refresh(gpc, gpa, len);
}
EXPORT_SYMBOL_GPL(kvm_gpc_activate);
-void kvm_gpc_deactivate(struct kvm *kvm, struct gfn_to_pfn_cache *gpc)
+void kvm_gpc_deactivate(struct gfn_to_pfn_cache *gpc)
{
+ struct kvm *kvm = gpc->kvm;
+ kvm_pfn_t old_pfn;
+ void *old_khva;
+
if (gpc->active) {
/*
* Deactivate the cache before removing it from the list, KVM
@@ -410,13 +393,26 @@ void kvm_gpc_deactivate(struct kvm *kvm, struct gfn_to_pfn_cache *gpc)
*/
write_lock_irq(&gpc->lock);
gpc->active = false;
+ gpc->valid = false;
+
+ /*
+ * Leave the GPA => uHVA cache intact, it's protected by the
+ * memslot generation. The PFN lookup needs to be redone every
+ * time as mmu_notifier protection is lost when the cache is
+ * removed from the VM's gpc_list.
+ */
+ old_khva = gpc->khva - offset_in_page(gpc->khva);
+ gpc->khva = NULL;
+
+ old_pfn = gpc->pfn;
+ gpc->pfn = KVM_PFN_ERR_FAULT;
write_unlock_irq(&gpc->lock);
spin_lock(&kvm->gpc_lock);
list_del(&gpc->list);
spin_unlock(&kvm->gpc_lock);
- kvm_gfn_to_pfn_cache_unmap(kvm, gpc);
+ gpc_unmap_khva(old_pfn, old_khva);
}
}
EXPORT_SYMBOL_GPL(kvm_gpc_deactivate);