From: Sean Christopherson <seanjc@xxxxxxxxxx>
[ Upstream commit 2644312052d54e2e7543c7d186899a36ed22f0bf ]
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: 660a5d517aaa ("KVM: x86: save/load state on SMM switch")
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Message-Id: <20210205012458.3872687-3-seanjc@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/x86/kvm/emulate.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 66a08322988f2..1453b9b794425 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -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 & DR6_VOLATILE) | DR6_FIXED_1))
return X86EMUL_UNHANDLEABLE;
- val = GET_SMSTATE(u32, smstate, 0x7f60);
+ val = GET_SMSTATE(u64, smstate, 0x7f60);
if (ctxt->ops->set_dr(ctxt, 7, (val & DR7_VOLATILE) | DR7_FIXED_1))
return X86EMUL_UNHANDLEABLE;
--
2.27.0
