Messages in this thread Patch in this message | | | Date | Wed, 16 Dec 2020 17:04:09 -0800 | Subject | [PATCH] x86/sev-es: Fix SEV-ES OUT/IN immediate opcode vc handling | From | Peter Gonda <> |
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The IN and OUT immediate instructions only use an 8-bit immediate. The current VC handler uses the entire 32-bit immediate value. These instructions only set the first bytes.
Tested with a loop back port with "outb %0,$0xe0". Before the port seen by KVM was 0xffffffffffffffe0 instead of 0xe0. After the correct port was seen by KVM and the guests loop back OUT then IN were equal.
Signed-off-by: Peter Gonda <pgonda@google.com> Acked-by: David Rientjes <rientjes@google.com>
--- arch/x86/kernel/sev-es-shared.c | 8 ++++++-- drivers/Makefile | 1 + 2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/sev-es-shared.c b/arch/x86/kernel/sev-es-shared.c index 7d04b356d44d..6c790377c55c 100644 --- a/arch/x86/kernel/sev-es-shared.c +++ b/arch/x86/kernel/sev-es-shared.c @@ -305,14 +305,14 @@ static enum es_result vc_ioio_exitinfo(struct es_em_ctxt *ctxt, u64 *exitinfo) case 0xe4: case 0xe5: *exitinfo |= IOIO_TYPE_IN; - *exitinfo |= (u64)insn->immediate.value << 16; + *exitinfo |= insn->immediate.bytes[0] << 16; break; /* OUT immediate opcodes */ case 0xe6: case 0xe7: *exitinfo |= IOIO_TYPE_OUT; - *exitinfo |= (u64)insn->immediate.value << 16; + *exitinfo |= insn->immediate.bytes[0] << 16; break;
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