[PATCH v3 03/22] kvm: x86: Fix xstate_required_size() to follow XSTATE alignment rule

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



CPUID.0xD.1.EBX enumerates the size of the XSAVE area (in compacted
format) required by XSAVES. If CPUID.0xD.i.ECX[1] is set for a state
component (i), this state component should be located on the next
64-bytes boundary following the preceding state component in the
compacted layout.

Fix xstate_required_size() to follow the alignment rule. AMX is the
first state component with 64-bytes alignment to catch this bug.

Signed-off-by: Yang Zhong <yang.zhong@xxxxxxxxx>
Signed-off-by: Jing Liu <jing2.liu@xxxxxxxxx>
---
 arch/x86/kvm/cpuid.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 07e9215e911d..148003e26cbb 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -42,7 +42,8 @@ static u32 xstate_required_size(u64 xstate_bv, bool compacted)
 		if (xstate_bv & 0x1) {
 		        u32 eax, ebx, ecx, edx, offset;
 		        cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx);
-			offset = compacted ? ret : ebx;
+			/* ECX[1]: 64B alignment in compacted form */
+			offset = compacted ? ((ecx & 0x2) ? ALIGN(ret, 64) : ret) : ebx;
 			ret = max(ret, offset + eax);
 		}
 
-- 
2.27.0




[Index of Archives]     [Linux Wireless]     [Linux Kernel]     [ATH6KL]     [Linux Bluetooth]     [Linux Netdev]     [Kernel Newbies]     [Share Photos]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Samba]     [Device Mapper]

  Powered by Linux