Patch "KVM: selftests: Don't skip L2's VMCALL in SMM test for SVM guest" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    KVM: selftests: Don't skip L2's VMCALL in SMM test for SVM guest

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     kvm-selftests-don-t-skip-l2-s-vmcall-in-smm-test-for.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 7b713d1564ff5e689384ebc1786921b365f76215
Author: Sean Christopherson <seanjc@xxxxxxxxxx>
Date:   Tue Jan 25 22:17:25 2022 +0000

    KVM: selftests: Don't skip L2's VMCALL in SMM test for SVM guest
    
    [ Upstream commit 4cf3d3ebe8794c449af3e0e8c1d790c97e461d20 ]
    
    Don't skip the vmcall() in l2_guest_code() prior to re-entering L2, doing
    so will result in L2 running to completion, popping '0' off the stack for
    RET, jumping to address '0', and ultimately dying with a triple fault
    shutdown.
    
    It's not at all obvious why the test re-enters L2 and re-executes VMCALL,
    but presumably it serves a purpose.  The VMX path doesn't skip vmcall(),
    and the test can't possibly have passed on SVM, so just do what VMX does.
    
    Fixes: d951b2210c1a ("KVM: selftests: smm_test: Test SMM enter from L2")
    Cc: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
    Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
    Message-Id: <20220125221725.2101126-1-seanjc@xxxxxxxxxx>
    Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
    Tested-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
    Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/tools/testing/selftests/kvm/x86_64/smm_test.c b/tools/testing/selftests/kvm/x86_64/smm_test.c
index d0fe2fdce58c4..db2a17559c3d5 100644
--- a/tools/testing/selftests/kvm/x86_64/smm_test.c
+++ b/tools/testing/selftests/kvm/x86_64/smm_test.c
@@ -105,7 +105,6 @@ static void guest_code(void *arg)
 
 		if (cpu_has_svm()) {
 			run_guest(svm->vmcb, svm->vmcb_gpa);
-			svm->vmcb->save.rip += 3;
 			run_guest(svm->vmcb, svm->vmcb_gpa);
 		} else {
 			vmlaunch();