[PATCH 5.4 365/388] KVM: SVM: Add a dedicated INVD intercept routine

From: Greg Kroah-Hartman
Date: Tue Sep 29 2020 - 07:55:36 EST


From: Tom Lendacky <thomas.lendacky@xxxxxxx>

[ Upstream commit 4bb05f30483fd21ea5413eaf1182768f251cf625 ]

The INVD instruction intercept performs emulation. Emulation can't be done
on an SEV guest because the guest memory is encrypted.

Provide a dedicated intercept routine for the INVD intercept. And since
the instruction is emulated as a NOP, just skip it instead.

Fixes: 1654efcbc431 ("KVM: SVM: Add KVM_SEV_INIT command")
Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Message-Id: <a0b9a19ffa7fef86a3cc700c7ea01cb2731e04e5.1600972918.git.thomas.lendacky@xxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/x86/kvm/svm.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 802b5f9ab7446..b58495fde2e89 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3967,6 +3967,12 @@ static int iret_interception(struct vcpu_svm *svm)
return 1;
}

+static int invd_interception(struct vcpu_svm *svm)
+{
+ /* Treat an INVD instruction as a NOP and just skip it. */
+ return kvm_skip_emulated_instruction(&svm->vcpu);
+}
+
static int invlpg_interception(struct vcpu_svm *svm)
{
if (!static_cpu_has(X86_FEATURE_DECODEASSISTS))
@@ -4819,7 +4825,7 @@ static int (*const svm_exit_handlers[])(struct vcpu_svm *svm) = {
[SVM_EXIT_RDPMC] = rdpmc_interception,
[SVM_EXIT_CPUID] = cpuid_interception,
[SVM_EXIT_IRET] = iret_interception,
- [SVM_EXIT_INVD] = emulate_on_interception,
+ [SVM_EXIT_INVD] = invd_interception,
[SVM_EXIT_PAUSE] = pause_interception,
[SVM_EXIT_HLT] = halt_interception,
[SVM_EXIT_INVLPG] = invlpg_interception,
--
2.25.1