[PATCH v3 5/6] KVM: SEV: Perform RMP optimizations on SNP guest shutdown

[Ashish Kalra]

From: Ashish Kalra <ashish.kalra@xxxxxxx>

As SNP guests are launched, pages converted to private cause RMPUPDATE
to disable the corresponding RMPOPT optimizations.

Conversely, during SNP guest termination, when guest pages are
converted back to shared and are not assigned, RMPOPT will be used
to re-enable RMP optimizations.

RMP optimizations are performed asynchronously by queuing work on a
dedicated workqueue with a delay.

Delaying work allows batching of multiple SNP guest terminations.

Signed-off-by: Ashish Kalra <ashish.kalra@xxxxxxx>
---
 arch/x86/kvm/svm/sev.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 3f9c1aa39a0a..2ad4727c4177 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2942,6 +2942,8 @@ void sev_vm_destroy(struct kvm *kvm)
 	if (sev_snp_guest(kvm)) {
 		snp_guest_req_cleanup(kvm);
 
+		snp_perform_rmp_optimization();
+
 		/*
 		 * Decomission handles unbinding of the ASID. If it fails for
 		 * some unexpected reason, just leak the ASID.
-- 
2.43.0