Commit 0d3518d2 authored by Mingwei Zhang's avatar Mingwei Zhang Committed by Sean Christopherson
Browse files

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: e79b91bb ("KVM: SVM: use vmsave/vmload for saving/restoring additional host state")
Reported-by: default avatarVenkatesh Srinivas <venkateshs@google.com>
Suggested-by: default avatarJim Mattson <jmattson@google.com>
Signed-off-by: default avatarMingwei Zhang <mizhang@google.com>
Link: https://lore.kernel.org/r/20230523165635.4002711-1-mizhang@google.com


[sean: massage changelog]
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent b9846a69

arch/x86/kvm/svm/svm.c

+0 −24
Original line number Diff line number Diff line
@@ -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);

arch/x86/kvm/svm/svm.h

+0 −1
Original line number Diff line number Diff line
@@ -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;