The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

Possible dependencies:

055f37f84e30 ("KVM: x86: emulator: update the emulation mode after rsm") 0128116550ac ("KVM: x86: Drop .post_leave_smm(), i.e. the manual post-RSM MMU reset") fa75e08bbe4f ("KVM: x86: Invoke kvm_smm_changed() immediately after clearing SMM flag") edce46548b70 ("KVM: x86: Replace .set_hflags() with dedicated .exiting_smm() helper") 25b17226cd9a ("KVM: x86: Emulate triple fault shutdown if RSM emulation fails") 78fcb2c91adf ("KVM: x86: Immediately reset the MMU context when the SMM flag is cleared") 02d4160fbd76 ("x86: KVM: add xsetbv to the emulator") 9ec19493fb86 ("KVM: x86: clear SMM flags before loading state while leaving SMM") c5833c7a43a6 ("KVM: x86: Open code kvm_set_hflags") ed19321fb657 ("KVM: x86: Load SMRAM in a single shot when leaving SMM") a821bab2d1ee ("KVM: VMX: Move VMX specific files to a "vmx" subdirectory") a633e41e7362 ("KVM: nVMX: assimilate nested_vmx_entry_failure() into nested_vmx_enter_non_root_mode()") 7671ce21b13b ("KVM: nVMX: move check_vmentry_postreqs() call to nested_vmx_enter_non_root_mode()") d63907dc7dd1 ("KVM: nVMX: rename enter_vmx_non_root_mode to nested_vmx_enter_non_root_mode")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 055f37f84e304e59c046d1accfd8f08462f52c4c Mon Sep 17 00:00:00 2001 From: Maxim Levitsky mlevitsk@redhat.com Date: Tue, 25 Oct 2022 15:47:30 +0300 Subject: [PATCH] KVM: x86: emulator: update the emulation mode after rsm

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@redhat.com Message-Id: 20221025124741.228045-13-mlevitsk@redhat.com Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini pbonzini@redhat.com

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index e5522a23d985..33385ebae100 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2662,7 +2662,7 @@ static int em_rsm(struct x86_emulate_ctxt *ctxt) * those side effects need to be explicitly handled for both success * and shutdown. */ - return X86EMUL_CONTINUE; + return emulator_recalc_and_set_mode(ctxt);

emulate_shutdown: ctxt->ops->triple_fault(ctxt);