From 0fc5deae03a2724a4b18373b2e6a3b585019de1e Mon Sep 17 00:00:00 2001 From: Tom Lendacky Date: Thu, 3 Oct 2019 21:17:46 +0000 Subject: KVM: SVM: Remove unneeded WBINVD and DF_FLUSH when starting SEV guests Performing a WBINVD and DF_FLUSH are expensive operations. The SEV support currently performs this WBINVD/DF_FLUSH combination when an SEV guest is terminated, so there is no need for it to be done before LAUNCH. However, when the SEV firmware transitions the platform from UNINIT state to INIT state, all ASIDs will be marked invalid across all threads. Therefore, as part of transitioning the platform to INIT state, perform a WBINVD/DF_FLUSH after a successful INIT in the PSP/SEV device driver. Since the PSP/SEV device driver is x86 only, it can reference and use the WBINVD related functions directly. Cc: Gary Hook Cc: Herbert Xu Cc: "David S. Miller" Tested-by: David Rientjes Signed-off-by: Tom Lendacky Signed-off-by: Paolo Bonzini --- arch/x86/kvm/svm.c | 15 --------------- 1 file changed, 15 deletions(-) (limited to 'arch/x86/kvm') diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 1d217680cf83..389dfd7594eb 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -6329,21 +6329,6 @@ static int sev_bind_asid(struct kvm *kvm, unsigned int handle, int *error) int asid = sev_get_asid(kvm); int ret; - /* - * Guard against a DEACTIVATE command before the DF_FLUSH command - * has completed. - */ - mutex_lock(&sev_deactivate_lock); - - wbinvd_on_all_cpus(); - - ret = sev_guest_df_flush(error); - - mutex_unlock(&sev_deactivate_lock); - - if (ret) - return ret; - data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT); if (!data) return -ENOMEM; -- cgit v1.2.3