This is a note to let you know that I've just added the patch titled
selftests: kvm: set rax before vmcall
to the 5.18-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:
selftests-kvm-set-rax-before-vmcall.patch
and it can be found in the queue-5.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 9b05d8c196047a5c813e312cdad53d52934e6cb1
Author: Andrei Vagin <avagin@xxxxxxxxxx>
Date: Fri Jul 22 16:02:40 2022 -0700
selftests: kvm: set rax before vmcall
[ Upstream commit 281106f938d3daaea6f8b6723a8217a2a1ef6936 ]
kvm_hypercall has to place the hypercall number in rax.
Trace events show that kvm_pv_test doesn't work properly:
kvm_pv_test-53132: kvm_hypercall: nr 0x0 a0 0x0 a1 0x0 a2 0x0 a3 0x0
kvm_pv_test-53132: kvm_hypercall: nr 0x0 a0 0x0 a1 0x0 a2 0x0 a3 0x0
kvm_pv_test-53132: kvm_hypercall: nr 0x0 a0 0x0 a1 0x0 a2 0x0 a3 0x0
With this change, it starts working as expected:
kvm_pv_test-54285: kvm_hypercall: nr 0x5 a0 0x0 a1 0x0 a2 0x0 a3 0x0
kvm_pv_test-54285: kvm_hypercall: nr 0xa a0 0x0 a1 0x0 a2 0x0 a3 0x0
kvm_pv_test-54285: kvm_hypercall: nr 0xb a0 0x0 a1 0x0 a2 0x0 a3 0x0
Signed-off-by: Andrei Vagin <avagin@xxxxxxxxxx>
Message-Id: <20220722230241.1944655-5-avagin@xxxxxxxxxx>
Fixes: ac4a4d6de22e ("selftests: kvm: test enforcement of paravirtual cpuid features")
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index 33ea5e9955d9..b9984124a294 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -1423,7 +1423,7 @@ uint64_t kvm_hypercall(uint64_t nr, uint64_t a0, uint64_t a1, uint64_t a2,
asm volatile("vmcall"
: "=a"(r)
- : "b"(a0), "c"(a1), "d"(a2), "S"(a3));
+ : "a"(nr), "b"(a0), "c"(a1), "d"(a2), "S"(a3));
return r;
}
