From: Brijesh Singh <brijesh.singh@amd.com>
Date: Mon, 4 Dec 2017 10:57:25 -0600
Subject: KVM: SVM: Prepare to reserve asid for SEV guest
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Git-commit: 4faefff3241e02dd66bfb77bd7ca40f3aa08f62e
Patch-mainline: v4.16-rc1
References: bsc#1063068

Currently, ASID allocation start at 1. Add a svm_vcpu_data.min_asid
which allows supplying a dynamic start ASID.

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
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.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
@@ -524,6 +524,7 @@ struct svm_cpu_data {
 	u64 asid_generation;
 	u32 max_asid;
 	u32 next_asid;
+	u32 min_asid;
 	struct kvm_ldttss_desc *tss_desc;
 
 	struct page *save_area;
@@ -781,6 +782,7 @@ 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;
 
 	gdt = get_current_gdt_rw();
 	sd->tss_desc = (struct kvm_ldttss_desc *)(gdt + GDT_ENTRY_TSS);
@@ -2087,7 +2089,7 @@ static void new_asid(struct vcpu_svm *sv
 {
 	if (sd->next_asid > sd->max_asid) {
 		++sd->asid_generation;
-		sd->next_asid = 1;
+		sd->next_asid = sd->min_asid;
 		svm->vmcb->control.tlb_ctl = TLB_CONTROL_FLUSH_ALL_ASID;
 	}