Old KVM guests invoke single-context invvpid without actually checking
whether it is supported. This was fixed by commit 518c8ae ("KVM: VMX:
Make sure single type invvpid is supported before issuing invvpid
instruction", 2010-08-01) and the patch after, but pre-2.6.36
kernels lack it including RHEL 6.
Reported-by: jmont...@redhat.com
Cc: sta...@vger.kernel.org
Fixes: 99b83ac893b84ed1a62ad6d1f2b6cc32026b9e85
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
arch/x86/kvm/vmx.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 728f31bd350e..5cf66c14aac0 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2712,8 +2712,15 @@ static void nested_vmx_setup_ctls_msrs(struct vcpu_vmx
*vmx)
} else
vmx->nested.nested_vmx_ept_caps = 0;
+ /*
+ * Old versions of KVM use the single-context version without
+ * checking for support, so declare that it is supported even
+ * though it is treated as global context. The alternative is
+ * not failing the single-context invvpid, and it is worse.
+ */
if (enable_vpid)
vmx->nested.nested_vmx_vpid_caps = VMX_VPID_INVVPID_BIT |
+ VMX_VPID_EXTENT_SINGLE_CONTEXT_BIT |
VMX_VPID_EXTENT_GLOBAL_CONTEXT_BIT;
else
vmx->nested.nested_vmx_vpid_caps = 0;
@@ -7475,12 +7482,17 @@ static int handle_invvpid(struct kvm_vcpu *vcpu)
}
switch (type) {
+ case VMX_VPID_EXTENT_SINGLE_CONTEXT:
+ /*
+ * Old versions of KVM use the single-context version so we
+ * have to support it; just treat it the same as all-context.
+ */
case VMX_VPID_EXTENT_ALL_CONTEXT:
__vmx_flush_tlb(vcpu, to_vmx(vcpu)->nested.vpid02);
nested_vmx_succeed(vcpu);
break;
default:
- /* Trap single context invalidation invvpid calls */
+ /* Trap individual address invalidation invvpid calls */
BUG_ON(1);
break;
}
--
1.8.3.1
