[PATCH v5 29/34] KVM: SVM: Set the encryption mask for the SVM host save area

From: Tom Lendacky <thomas.lendacky@amd.com>
To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	Sean Christopherson <seanjc@google.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Borislav Petkov <bp@alien8.de>, Ingo Molnar <mingo@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Brijesh Singh <brijesh.singh@amd.com>
Subject: [PATCH v5 29/34] KVM: SVM: Set the encryption mask for the SVM host save area
Date: Thu, 10 Dec 2020 11:10:04 -0600	[thread overview]
Message-ID: <b77aa28af6d7f1a0cb545959e08d6dc75e0c3cba.1607620209.git.thomas.lendacky@amd.com> (raw)
In-Reply-To: <cover.1607620209.git.thomas.lendacky@amd.com>

From: Tom Lendacky <thomas.lendacky@amd.com>

The SVM host save area is used to restore some host state on VMEXIT of an
SEV-ES guest. After allocating the save area, clear it and add the
encryption mask to the SVM host save area physical address that is
programmed into the VM_HSAVE_PA MSR.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
 arch/x86/kvm/svm/sev.c | 1 -
 arch/x86/kvm/svm/svm.c | 3 ++-
 arch/x86/kvm/svm/svm.h | 2 ++
 3 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 486c5609fa25..4797a6768eaf 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -32,7 +32,6 @@ unsigned int max_sev_asid;
 static unsigned int min_sev_asid;
 static unsigned long *sev_asid_bitmap;
 static unsigned long *sev_reclaim_asid_bitmap;
-#define __sme_page_pa(x) __sme_set(page_to_pfn(x) << PAGE_SHIFT)
 
 struct enc_region {
 	struct list_head list;
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 16746bc6a1fa..d8217ba6791f 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -498,7 +498,7 @@ static int svm_hardware_enable(void)
 
 	wrmsrl(MSR_EFER, efer | EFER_SVME);
 
-	wrmsrl(MSR_VM_HSAVE_PA, page_to_pfn(sd->save_area) << PAGE_SHIFT);
+	wrmsrl(MSR_VM_HSAVE_PA, __sme_page_pa(sd->save_area));
 
 	if (static_cpu_has(X86_FEATURE_TSCRATEMSR)) {
 		wrmsrl(MSR_AMD64_TSC_RATIO, TSC_RATIO_DEFAULT);
@@ -566,6 +566,7 @@ static int svm_cpu_init(int cpu)
 	sd->save_area = alloc_page(GFP_KERNEL);
 	if (!sd->save_area)
 		goto free_cpu_data;
+	clear_page(page_address(sd->save_area));
 
 	if (svm_sev_enabled()) {
 		sd->sev_vmcbs = kmalloc_array(max_sev_asid + 1,
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 5d570d5a6a2c..313cfb733f7e 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -21,6 +21,8 @@
 
 #include <asm/svm.h>
 
+#define __sme_page_pa(x) __sme_set(page_to_pfn(x) << PAGE_SHIFT)
+
 static const u32 host_save_user_msrs[] = {
 #ifdef CONFIG_X86_64
 	MSR_STAR, MSR_LSTAR, MSR_CSTAR, MSR_SYSCALL_MASK, MSR_KERNEL_GS_BASE,
-- 
2.28.0

