KVM: nSVM: Track the ASID generation of the vmcb vmrun through the vmcb

This patch moves the asid_generation from the vcpu to the vmcb
in order to track the ASID generation that was active the last
time the vmcb was run. If sd->asid_generation changes between
two runs, the old ASID is invalid and must be changed.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Cathy Avery <cavery@redhat.com>
Message-Id: <20210112164313.4204-3-cavery@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index a6b02f6..8779b7b 100644 (file)
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1229,7 +1229,7 @@ static void init_vmcb(struct vcpu_svm *svm)
                save->cr3 = 0;
                save->cr4 = 0;
        }
-       svm->asid_generation = 0;
+       svm->current_vmcb->asid_generation = 0;
        svm->asid = 0;
 
        svm->nested.vmcb12_gpa = 0;
@@ -1312,13 +1312,6 @@ void svm_switch_vmcb(struct vcpu_svm *svm, struct kvm_vmcb_info *target_vmcb)
        svm->vmcb_pa = target_vmcb->pa;
 
        /*
-       * Workaround: we don't yet track the ASID generation
-       * that was active the last time target_vmcb was run.
-       */
-
-       svm->asid_generation = 0;
-
-       /*
        * Track the physical CPU the target_vmcb is running on
        * in order to mark the VMCB dirty if the cpu changes at
        * its next vmrun.
@@ -1384,7 +1377,6 @@ static int svm_create_vcpu(struct kvm_vcpu *vcpu)
        if (vmsa_page)
                svm->vmsa = page_address(vmsa_page);
 
-       svm->asid_generation = 0;
        svm->guest_state_loaded = false;
 
        svm_switch_vmcb(svm, &svm->vmcb01);
@@ -1866,7 +1858,7 @@ static void new_asid(struct vcpu_svm *svm, struct svm_cpu_data *sd)
                vmcb_mark_dirty(svm->vmcb, VMCB_ASID);
        }
 
-       svm->asid_generation = sd->asid_generation;
+       svm->current_vmcb->asid_generation = sd->asid_generation;
        svm->asid = sd->next_asid++;
 }
 
@@ -3434,10 +3426,11 @@ static void pre_svm_run(struct vcpu_svm *svm)
        /*
         * If the previous vmrun of the vmcb occurred on
         * a different physical cpu then we must mark the vmcb dirty.
-        */
+        * and assign a new asid.
+       */
 
         if (unlikely(svm->current_vmcb->cpu != svm->vcpu.cpu)) {
-               svm->asid_generation = 0;
+               svm->current_vmcb->asid_generation = 0;
                vmcb_mark_all_dirty(svm->vmcb);
                svm->current_vmcb->cpu = svm->vcpu.cpu;
         }
@@ -3446,7 +3439,7 @@ static void pre_svm_run(struct vcpu_svm *svm)
                return pre_sev_run(svm, svm->vcpu.cpu);
 
        /* FIXME: handle wraparound of asid_generation */
-       if (svm->asid_generation != sd->asid_generation)
+       if (svm->current_vmcb->asid_generation != sd->asid_generation)
                new_asid(svm, sd);
 }
 
@@ -3670,7 +3663,7 @@ void svm_flush_tlb(struct kvm_vcpu *vcpu)
        if (static_cpu_has(X86_FEATURE_FLUSHBYASID))
                svm->vmcb->control.tlb_ctl = TLB_CONTROL_FLUSH_ASID;
        else
-               svm->asid_generation--;
+               svm->current_vmcb->asid_generation--;
 }
 
 static void svm_flush_tlb_gva(struct kvm_vcpu *vcpu, gva_t gva)

diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index a372810..9931551 100644 (file)
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -85,6 +85,7 @@ struct kvm_vmcb_info {
        struct vmcb *ptr;
        unsigned long pa;
        int cpu;
+       uint64_t asid_generation;
 };
 
 struct svm_nested_state {
@@ -114,7 +115,6 @@ struct vcpu_svm {
        struct kvm_vmcb_info *current_vmcb;
        struct svm_cpu_data *svm_data;
        u32 asid;
-       uint64_t asid_generation;
        uint64_t sysenter_esp;
        uint64_t sysenter_eip;
        uint64_t tsc_aux;