From: "Roth, Michael" <Michael.Roth@amd.com>
To: <devel@edk2.groups.io>
Cc: Tom Lendacky <thomas.lendacky@amd.com>, <ray.ni@intel.com>
Subject: [PATCH 4/4] OvmfPkg/CcExitLib: Use documented XSave area base size for SEV-SNP
Date: Wed, 21 Dec 2022 10:06:51 -0600 [thread overview]
Message-ID: <20221221160651.182143-5-michael.roth@amd.com> (raw)
In-Reply-To: <20221221160651.182143-1-michael.roth@amd.com>
Currently OVMF tries to rely on the base size advertised via the CPUID
table entries corresponding to leaf 0xD, sub-leafs 0x0/0x1. This will
generally work for KVM guests, but might not for other SEV-SNP
hypervisor implementations. Make the handling more robust by simply
using the base area size documented by the APM.
Signed-off-by: Michael Roth <michael.roth@amd.com>
---
OvmfPkg/Library/CcExitLib/CcExitVcHandler.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/OvmfPkg/Library/CcExitLib/CcExitVcHandler.c b/OvmfPkg/Library/CcExitLib/CcExitVcHandler.c
index cd117d5a31..f985dcff8d 100644
--- a/OvmfPkg/Library/CcExitLib/CcExitVcHandler.c
+++ b/OvmfPkg/Library/CcExitLib/CcExitVcHandler.c
@@ -1647,8 +1647,6 @@ SnpEnabled (
@param[in] XFeaturesEnabled Bit-mask of enabled XSAVE features/areas as
indicated by XCR0/MSR_IA32_XSS bits
- @param[in] XSaveBaseSize Base/legacy XSAVE area size (e.g. when
- XCR0 is 1)
@param[in, out] XSaveSize Pointer to storage for calculated XSAVE area
size
@param[in] Compacted Whether or not the calculation is for the
@@ -1663,7 +1661,6 @@ STATIC
BOOLEAN
GetCpuidXSaveSize (
IN UINT64 XFeaturesEnabled,
- IN UINT32 XSaveBaseSize,
IN OUT UINT32 *XSaveSize,
IN BOOLEAN Compacted
)
@@ -1672,7 +1669,10 @@ GetCpuidXSaveSize (
UINT64 XFeaturesFound = 0;
UINT32 Idx;
- *XSaveSize = XSaveBaseSize;
+ //
+ // The base/legacy XSave size is documented to be 0x240 in the APM.
+ //
+ *XSaveSize = 0x240;
CpuidInfo = (SEV_SNP_CPUID_INFO *)(UINT64)PcdGet32 (PcdOvmfCpuidBase);
for (Idx = 0; Idx < CpuidInfo->Count; Idx++) {
@@ -1888,7 +1888,6 @@ GetCpuidFw (
if (!GetCpuidXSaveSize (
XCr0 | XssMsr.Uint64,
- *Ebx,
&XSaveSize,
Compacted
))
--
2.25.1
next prev parent reply other threads:[~2022-12-21 16:08 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-21 16:06 [PATCH 0/4] Fixes for SEV-SNP CC blob and CPUID table handling Roth, Michael
2022-12-21 16:06 ` [PATCH 1/4] OvmfPkg/AmdSevDxe: Allocate SEV-SNP CC blob as EfiACPIReclaimMemory Roth, Michael
2022-12-21 16:48 ` Lendacky, Thomas
2022-12-21 21:26 ` Dov Murik
2023-01-06 9:18 ` [edk2-devel] " Yao, Jiewen
2023-01-06 20:25 ` Dov Murik
2023-01-07 2:01 ` Yao, Jiewen
2023-01-07 16:52 ` Ard Biesheuvel
2023-01-12 10:15 ` Yao, Jiewen
2022-12-21 16:06 ` [PATCH 2/4] OvmfPkg/AmdSevDxe: Update ConfidentialComputing blob struct definition Roth, Michael
2023-01-06 9:14 ` [edk2-devel] " Yao, Jiewen
2022-12-21 16:06 ` [PATCH 3/4] OvmfPkg/CcExitLib: Fix SEV-SNP XSave area size calculation Roth, Michael
2022-12-21 16:52 ` Lendacky, Thomas
2023-01-06 8:53 ` [edk2-devel] " Yao, Jiewen
2022-12-21 16:06 ` Roth, Michael [this message]
2022-12-21 16:59 ` [PATCH 4/4] OvmfPkg/CcExitLib: Use documented XSave area base size for SEV-SNP Lendacky, Thomas
2023-01-06 8:53 ` [edk2-devel] " Yao, Jiewen
2022-12-21 17:41 ` [PATCH 0/4] Fixes for SEV-SNP CC blob and CPUID table handling Roth, Michael
2023-01-18 3:57 ` Yao, Jiewen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-list from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20221221160651.182143-5-michael.roth@amd.com \
--to=devel@edk2.groups.io \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox