[PATCH] x86/sev: Fix operator precedence in GHCB_MSR_VMPL_REQ_LEVEL macro
From: Seongmanlee
Date: Sat May 10 2025 - 12:27:42 EST
From: leonardo-leecaprio <augustus92@xxxxxxxxxxx>
The GHCB_MSR_VMPL_REQ_LEVEL macro lacked parentheses around the bitmask
expression, causing the shift operation to bind too early. As a result,
when switching to VMPL2 from VMPL1 (e.g., GHCB_MSR_VMPL_REQ_LEVEL(1)),
incorrect values such as 0x000000016 were generated instead of the intended
0x100000016.
This patch fixes the precedence issue by grouping the masked value
before applying the shift.
Signed-off-by: leonardo-leecaprio <augustus92@xxxxxxxxxxx>
---
arch/x86/include/asm/sev-common.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/sev-common.h b/arch/x86/include/asm/sev-common.h
index acb85b934..0020d77a0 100644
--- a/arch/x86/include/asm/sev-common.h
+++ b/arch/x86/include/asm/sev-common.h
@@ -116,7 +116,7 @@ enum psc_op {
#define GHCB_MSR_VMPL_REQ 0x016
#define GHCB_MSR_VMPL_REQ_LEVEL(v) \
/* GHCBData[39:32] */ \
- (((u64)(v) & GENMASK_ULL(7, 0) << 32) | \
+ ((((u64)(v) & GENMASK_ULL(7, 0)) << 32) | \
/* GHCBDdata[11:0] */ \
GHCB_MSR_VMPL_REQ)
--
2.39.5 (Apple Git-154)