From: Sean Christopherson <seanjc@google.com>
To: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
Zheyun Shen <szy0127@sjtu.edu.cn>,
Tom Lendacky <thomas.lendacky@amd.com>,
Kevin Loughlin <kevinloughlin@google.com>,
Mingwei Zhang <mizhang@google.com>
Subject: [PATCH 1/7] KVM: SVM: Remove wbinvd in sev_vm_destroy()
Date: Wed, 26 Feb 2025 17:48:52 -0800 [thread overview]
Message-ID: <20250227014858.3244505-2-seanjc@google.com> (raw)
In-Reply-To: <20250227014858.3244505-1-seanjc@google.com>
From: Zheyun Shen <szy0127@sjtu.edu.cn>
Before sev_vm_destroy() is called, kvm_arch_guest_memory_reclaimed()
has been called for SEV and SEV-ES and kvm_arch_gmem_invalidate()
has been called for SEV-SNP. These functions have already handled
flushing the memory. Therefore, this wbinvd_on_all_cpus() can
simply be dropped.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Zheyun Shen <szy0127@sjtu.edu.cn>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/svm/sev.c | 6 ------
1 file changed, 6 deletions(-)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 74525651770a..d934d788ac39 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2879,12 +2879,6 @@ void sev_vm_destroy(struct kvm *kvm)
return;
}
- /*
- * Ensure that all guest tagged cache entries are flushed before
- * releasing the pages back to the system for use. CLFLUSH will
- * not do this, so issue a WBINVD.
- */
- wbinvd_on_all_cpus();
/*
* if userspace was terminated before unregistering the memory regions
--
2.48.1.711.g2feabab25a-goog
next prev parent reply other threads:[~2025-02-27 1:49 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-27 1:48 [PATCH 0/7] x86, KVM: Optimize SEV cache flushing Sean Christopherson
2025-02-27 1:48 ` Sean Christopherson [this message]
2025-02-27 1:48 ` [PATCH 2/7] x86, lib: Drop the unused return value from wbinvd_on_all_cpus() Sean Christopherson
2025-02-27 19:59 ` Sean Christopherson
2025-02-27 1:48 ` [PATCH 3/7] x86, lib: Add WBNOINVD helper functions Sean Christopherson
2025-03-13 10:13 ` Huang, Kai
2025-02-27 1:48 ` [PATCH 4/7] KVM: SEV: Prefer WBNOINVD over WBINVD for cache maintenance efficiency Sean Christopherson
2025-02-27 1:48 ` [PATCH 5/7] KVM: x86: Use wbinvd_on_cpu() instead of an open-coded equivalent Sean Christopherson
2025-03-03 16:49 ` Tom Lendacky
2025-02-27 1:48 ` [PATCH 6/7] x86, lib: Add wbinvd and wbnoinvd helpers to target multiple CPUs Sean Christopherson
2025-02-27 12:45 ` Zheyun Shen
2025-03-13 10:19 ` Huang, Kai
2025-02-27 1:48 ` [PATCH 7/7] KVM: SVM: Flush cache only on CPUs running SEV guest Sean Christopherson
2025-03-03 16:53 ` Tom Lendacky
2025-03-03 16:46 ` [PATCH 0/7] x86, KVM: Optimize SEV cache flushing Tom Lendacky
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