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Commit baa7e81e authored by Avi Kivity's avatar Avi Kivity Committed by Marcelo Tosatti
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KVM: VMX: Separate saving pre-realmode state from setting segments 



Commit b246dd5d ("KVM: VMX: Fix KVM_SET_SREGS with big real mode
segments") moved fix_rmode_seg() to vmx_set_segment(), so that it is
applied not just on transitions to real mode, but also on KVM_SET_SREGS
(migration).  However fix_rmode_seg() not only munges the vmcs segments,
it also sets up the save area for us to restore when returning to
protected mode or to return in vmx_get_segment().

Move saving the segment into a new function, save_rmode_seg(), and
call it just during the transition.

Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent dd856efa

arch/x86/kvm/vmx.c

+13 −7
Original line number Diff line number Diff line
@@ -2768,7 +2768,7 @@ static gva_t rmode_tss_base(struct kvm *kvm) 
	return kvm->arch.tss_addr;

}



static void fix_rmode_seg(int seg, struct kvm_save_segment *save)

static void save_rmode_seg(int seg, struct kvm_save_segment *save)

{

	struct kvm_vmx_segment_field *sf = &kvm_vmx_segment_fields[seg];
@@ -2776,6 +2776,12 @@ static void fix_rmode_seg(int seg, struct kvm_save_segment *save) 
	save->base = vmcs_readl(sf->base);

	save->limit = vmcs_read32(sf->limit);

	save->ar = vmcs_read32(sf->ar_bytes);

}



static void fix_rmode_seg(int seg, struct kvm_save_segment *save)

{

	struct kvm_vmx_segment_field *sf = &kvm_vmx_segment_fields[seg];



	vmcs_write16(sf->selector, save->base >> 4);

	vmcs_write32(sf->base, save->base & 0xffff0);

	vmcs_write32(sf->limit, 0xffff);
@@ -2798,6 +2804,12 @@ static void enter_rmode(struct kvm_vcpu *vcpu) 
	vmx->emulation_required = 1;

	vmx->rmode.vm86_active = 1;



	save_rmode_seg(VCPU_SREG_TR, &vmx->rmode.tr);

	save_rmode_seg(VCPU_SREG_ES, &vmx->rmode.es);

	save_rmode_seg(VCPU_SREG_DS, &vmx->rmode.ds);

	save_rmode_seg(VCPU_SREG_FS, &vmx->rmode.fs);

	save_rmode_seg(VCPU_SREG_GS, &vmx->rmode.gs);



	/*

	 * Very old userspace does not call KVM_SET_TSS_ADDR before entering

	 * vcpu. Call it here with phys address pointing 16M below 4G.
@@ -2812,14 +2824,8 @@ static void enter_rmode(struct kvm_vcpu *vcpu) 


	vmx_segment_cache_clear(vmx);



	vmx->rmode.tr.selector = vmcs_read16(GUEST_TR_SELECTOR);

	vmx->rmode.tr.base = vmcs_readl(GUEST_TR_BASE);

	vmcs_writel(GUEST_TR_BASE, rmode_tss_base(vcpu->kvm));



	vmx->rmode.tr.limit = vmcs_read32(GUEST_TR_LIMIT);

	vmcs_write32(GUEST_TR_LIMIT, RMODE_TSS_SIZE - 1);



	vmx->rmode.tr.ar = vmcs_read32(GUEST_TR_AR_BYTES);

	vmcs_write32(GUEST_TR_AR_BYTES, 0x008b);



	flags = vmcs_readl(GUEST_RFLAGS);