From: Brijesh Singh <brijesh.singh@amd.com>
Date: Mon, 4 Dec 2017 10:57:32 -0600
Subject: KVM: SVM: Reserve ASID range for SEV guest
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Git-commit: ed3cd233f8074015e164547abfcdd4678fd10bb4
Patch-mainline: v4.16-rc1
References: bsc#1063068

A SEV-enabled guest must use ASIDs from the defined subset, while non-SEV
guests can use the remaining ASID range. The range of allowed SEV guest
ASIDs is [1 - CPUID_8000_001F[ECX][31:0]].

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Improvements-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/kvm/svm.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -318,6 +318,8 @@ enum {
 
 #define VMCB_AVIC_APIC_BAR_MASK		0xFFFFFFFFFF000ULL
 
+static unsigned int max_sev_asid;
+
 static inline void mark_all_dirty(struct vmcb *vmcb)
 {
 	vmcb->control.clean = 0;
@@ -782,7 +784,7 @@ static int svm_hardware_enable(void)
 	sd->asid_generation = 1;
 	sd->max_asid = cpuid_ebx(SVM_CPUID_FUNC) - 1;
 	sd->next_asid = sd->max_asid + 1;
-	sd->min_asid = 1;
+	sd->min_asid = max_sev_asid + 1;
 
 	gdt = get_current_gdt_rw();
 	sd->tss_desc = (struct kvm_ldttss_desc *)(gdt + GDT_ENTRY_TSS);