Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b3dbf89e authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: SVM: Don't save/restore host cr2 



The host never reads cr2 in process context, so are free to clobber it.  The
vmx code does this, so we can safely remove the save/restore code.

Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent d3edefc0

arch/x86/kvm/svm.c

+0 −17
Original line number Diff line number Diff line
@@ -81,7 +81,6 @@ struct vcpu_svm { 


	u64 host_user_msrs[NR_HOST_SAVE_USER_MSRS];

	u64 host_gs_base;

	unsigned long host_cr2;



	u32 *msrpm;

	struct vmcb *hsave;
@@ -186,19 +185,6 @@ static inline void invlpga(unsigned long addr, u32 asid) 
	asm volatile (__ex(SVM_INVLPGA) :: "a"(addr), "c"(asid));

}



static inline unsigned long kvm_read_cr2(void)

{

	unsigned long cr2;



	asm volatile ("mov %%cr2, %0" : "=r" (cr2));

	return cr2;

}



static inline void kvm_write_cr2(unsigned long val)

{

	asm volatile ("mov %0, %%cr2" :: "r" (val));

}



static inline void force_new_asid(struct kvm_vcpu *vcpu)

{

	to_svm(vcpu)->asid_generation--;
@@ -2527,7 +2513,6 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	fs_selector = kvm_read_fs();

	gs_selector = kvm_read_gs();

	ldt_selector = kvm_read_ldt();

	svm->host_cr2 = kvm_read_cr2();

	if (!is_nested(svm))

		svm->vmcb->save.cr2 = vcpu->arch.cr2;

	/* required for live migration with NPT */
@@ -2614,8 +2599,6 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	vcpu->arch.regs[VCPU_REGS_RSP] = svm->vmcb->save.rsp;

	vcpu->arch.regs[VCPU_REGS_RIP] = svm->vmcb->save.rip;



	kvm_write_cr2(svm->host_cr2);



	kvm_load_fs(fs_selector);

	kvm_load_gs(gs_selector);

	kvm_load_ldt(ldt_selector);