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author | Paolo Bonzini <pbonzini@redhat.com> | 2022-12-06 12:29:06 -0500 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-12-12 15:54:07 -0500 |
commit | 9352e7470a1b4edd2fa9d235420ecc7bc3971bdc (patch) | |
tree | 141ccdb777f2ee36764f2067ab43f23da114e08a /virt | |
parent | 2afc1fbbdab2aee831561f09f859989dcd5ed648 (diff) | |
parent | 5656374b168c98377b6feee8d7500993eebda230 (diff) | |
download | lwn-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.c | 4 | ||||
-rw-r--r-- | virt/kvm/pfncache.c | 112 |
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); |