KVM: SVM: Remove TSS reloading code after VMEXIT

Remove the dedicated post-VMEXIT TSS reloading code now that KVM uses
VMLOAD to load host segment state, which includes TSS state.

Fixes: e79b91bb3c91 ("KVM: SVM: use vmsave/vmload for saving/restoring additional host state")
Reported-by: Venkatesh Srinivas <venkateshs@google.com>
Suggested-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Mingwei Zhang <mizhang@google.com>
Link: https://lore.kernel.org/r/20230523165635.4002711-1-mizhang@google.com
[sean: massage changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index ca32389f3c36bae9d4c2d29c7d810fde12bb82ff..616ea6f55ae5f8df36eeb566168ef371240c974d 100644 (file)
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -244,15 +244,6 @@ static u8 rsm_ins_bytes[] = "\x0f\xaa";
 
 static unsigned long iopm_base;
 
-struct kvm_ldttss_desc {
-       u16 limit0;
-       u16 base0;
-       unsigned base1:8, type:5, dpl:2, p:1;
-       unsigned limit1:4, zero0:3, g:1, base2:8;
-       u32 base3;
-       u32 zero1;
-} __attribute__((packed));
-
 DEFINE_PER_CPU(struct svm_cpu_data, svm_data);
 
 /*
@@ -588,7 +579,6 @@ static int svm_hardware_enable(void)
 
        struct svm_cpu_data *sd;
        uint64_t efer;
-       struct desc_struct *gdt;
        int me = raw_smp_processor_id();
 
        rdmsrl(MSR_EFER, efer);
@@ -601,9 +591,6 @@ static int svm_hardware_enable(void)
        sd->next_asid = sd->max_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);
-
        wrmsrl(MSR_EFER, efer | EFER_SVME);
 
        wrmsrl(MSR_VM_HSAVE_PA, sd->save_area_pa);
@@ -3457,14 +3444,6 @@ static int svm_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)
        return svm_invoke_exit_handler(vcpu, exit_code);
 }
 
-static void reload_tss(struct kvm_vcpu *vcpu)
-{
-       struct svm_cpu_data *sd = per_cpu_ptr(&svm_data, vcpu->cpu);
-
-       sd->tss_desc->type = 9; /* available 32/64-bit TSS */
-       load_TR_desc();
-}
-
 static void pre_svm_run(struct kvm_vcpu *vcpu)
 {
        struct svm_cpu_data *sd = per_cpu_ptr(&svm_data, vcpu->cpu);
@@ -4099,9 +4078,6 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu)
 
        svm_vcpu_enter_exit(vcpu, spec_ctrl_intercepted);
 
-       if (!sev_es_guest(vcpu->kvm))
-               reload_tss(vcpu);
-
        if (!static_cpu_has(X86_FEATURE_V_SPEC_CTRL))
                x86_spec_ctrl_restore_host(svm->virt_spec_ctrl);
 

diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index f44751dd8d5d9921ade844887b694d6ede0140af..18af7e712a5ae73d93cff78255eeb3fc2d0c5bb1 100644 (file)
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -303,7 +303,6 @@ struct svm_cpu_data {
        u32 max_asid;
        u32 next_asid;
        u32 min_asid;
-       struct kvm_ldttss_desc *tss_desc;
 
        struct page *save_area;
        unsigned long save_area_pa;