Merge tag 'kvm-x86-fixes-7.3-rc5' of https://github.com/kvm-x86/linux into HEAD

KVM fixes for 7.3-rcN

 - Fix a brown paper bag bug where KVM would incorrectly treat Intel PMU MSRs
   as valid on AMD.

 - Fix a regression in the hardware disable selftest where it checked the wrong
   macro when detecting glibc support (breaks at least musl).

 - Never clear KVM_REQ_VM_DEAD so that dead VMs stay dead, which is especially
   important for KVM_BUG_ON() flows, which often guard more dangerous bugs.

 - Re-pend GET_NESTED_STATE_PAGES if getting the pages fails, to fix a bug
   where KVM would let userspace run a broken setup with stale vmcs12 pages.

 - Fix a class of bugs where KVM would fail to fill kvm_run exit fields if
   getting nested pages failed.

 - Treat reserved entries in the memory attributes xarray as "no attributes",
   to fix false positives when checking for mixed attributes.

 - Fix memcg accounting for the memory attributes xarray (the xarray library
   subtly requires the xarray to be configured for accounting upfront; the gfp
   flags taken at runtime are used only rarely).

 - Don't pre-reserve xarray entries when storing empty attributes, as storing
   NULL must not require memory allocation (KVM and other subsystems heavily
   rely on this behavior).

1 files changed, 7 insertions, 2 deletions

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 03bfc92864b6..cf7fe835c4ad 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -2324,13 +2324,18 @@ static inline bool kvm_test_request(int req, struct kvm_vcpu *vcpu)
 	return test_bit(req & KVM_REQUEST_MASK, (void *)&vcpu->requests);
 }
 
-static inline void kvm_clear_request(int req, struct kvm_vcpu *vcpu)
+static __always_inline void kvm_clear_request(int req, struct kvm_vcpu *vcpu)
 {
+	BUILD_BUG_ON(req == KVM_REQ_VM_DEAD);
+
 	clear_bit(req & KVM_REQUEST_MASK, (void *)&vcpu->requests);
 }
 
-static inline bool kvm_check_request(int req, struct kvm_vcpu *vcpu)
+static __always_inline bool kvm_check_request(int req, struct kvm_vcpu *vcpu)
 {
+	/* Once a VM is dead, it needs to stay dead. */
+	BUILD_BUG_ON(req == KVM_REQ_VM_DEAD);
+
 	if (kvm_test_request(req, vcpu)) {
 		kvm_clear_request(req, vcpu);