Commit 26443120 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
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KVM: x86: Restore all 64 bits of DR6 and DR7 during RSM on x86-64 



Restore the full 64-bit values of DR6 and DR7 when emulating RSM on
x86-64, as defined by both Intel's SDM and AMD's APM.

Note, bits 63:32 of DR6 and DR7 are reserved, so this is a glorified nop
unless the SMM handler is poking into SMRAM, which it most definitely
shouldn't be doing since both Intel and AMD list the DR6 and DR7 fields
as read-only.

Fixes: 660a5d51 ("KVM: x86: save/load state on SMM switch")
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20210205012458.3872687-3-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 16d5163f

arch/x86/kvm/emulate.c

+2 −2
Original line number Diff line number Diff line
@@ -2564,12 +2564,12 @@ static int rsm_load_state_64(struct x86_emulate_ctxt *ctxt, 
	ctxt->_eip   = GET_SMSTATE(u64, smstate, 0x7f78);

	ctxt->eflags = GET_SMSTATE(u32, smstate, 0x7f70) | X86_EFLAGS_FIXED;



	val = GET_SMSTATE(u32, smstate, 0x7f68);

	val = GET_SMSTATE(u64, smstate, 0x7f68);



	if (ctxt->ops->set_dr(ctxt, 6, val))

		return X86EMUL_UNHANDLEABLE;



	val = GET_SMSTATE(u32, smstate, 0x7f60);

	val = GET_SMSTATE(u64, smstate, 0x7f60);



	if (ctxt->ops->set_dr(ctxt, 7, val))

		return X86EMUL_UNHANDLEABLE;