From: Maxim Levitsky <mlevitsk@xxxxxxxxxx> [ Upstream commit 055f37f84e304e59c046d1accfd8f08462f52c4c ] Update the emulation mode after RSM so that RIP will be correctly written back, because the RSM instruction can switch the CPU mode from 32 bit (or less) to 64 bit. This fixes a guest crash in case the #SMI is received while the guest runs a code from an address > 32 bit. Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx> Message-Id: <20221025124741.228045-13-mlevitsk@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- arch/x86/kvm/emulate.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 63efccc8f429..716d54b624e0 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2746,6 +2746,15 @@ static int em_rsm(struct x86_emulate_ctxt *ctxt) ctxt->ops->post_leave_smm(ctxt); + /* + * Note, the ctxt->ops callbacks are responsible for handling side + * effects when writing MSRs and CRs, e.g. MMU context resets, CPUID + * runtime updates, etc... If that changes, e.g. this flow is moved + * out of the emulator to make it look more like enter_smm(), then + * those side effects need to be explicitly handled for both success + * and shutdown. + */ + return X86EMUL_CONTINUE; } -- 2.35.1
