[PATCH v4 6/7] KVM: SEV: Perform RMP optimizations on SNP guest shutdown

[Ashish Kalra]

From: Ashish Kalra <ashish.kalra@xxxxxxx>

Pages are converted from shared to private as SNP guests are launched.
This destroys exisiting RMPOPT optimizations in the regions where
pages are converted.

Conversely, guest pages are converted back to shared during SNP guest
termination and their region may become eligible for RMPOPT
optimization.

To take advantage of this, perform RMPOPT after guest termination.
Do it after a delay so that a single RMPOPT pass can be done if
multiple guests terminate in a short period of time.

Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
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..e0f4f8ebef68 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_rmpopt_all_physmem();
+
 		/*
 		 * Decomission handles unbinding of the ASID. If it fails for
 		 * some unexpected reason, just leak the ASID.
-- 
2.43.0