[RFC PATCH v2 22/32] kvm: svm: prepare to reserve asid for SEV guest

From: Brijesh Singh
Date: Thu Mar 02 2017 - 10:56:13 EST


In current implementation, asid allocation starts from 1, this patch
adds a min_asid variable in svm_vcpu structure to allow starting asid
from something other than 1.

Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/svm.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index b581499..8d8fe62 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -507,6 +507,7 @@ 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;
@@ -763,6 +764,7 @@ 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;

native_store_gdt(&gdt_descr);
gdt = (struct desc_struct *)gdt_descr.address;
@@ -2026,7 +2028,7 @@ static void new_asid(struct vcpu_svm *svm, struct svm_cpu_data *sd)
{
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;
}