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From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
To: qemu-devel@nongnu.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	Chao Gao <chao.gao@intel.com>,
	antonio.gomez.iglesias@linux.intel.com,
	Daniel Sneddon <daniel.sneddon@linux.intel.com>
Subject: [PATCH] target/i386: Export RFDS bit to guests
Date: Wed, 13 Mar 2024 07:53:23 -0700	[thread overview]
Message-ID: <9a38877857392b5c2deae7e7db1b170d15510314.1710341348.git.pawan.kumar.gupta@linux.intel.com> (raw)

Register File Data Sampling (RFDS) is a CPU side-channel vulnerability
that may expose stale register value. CPUs that set RFDS_NO bit in MSR
IA32_ARCH_CAPABILITIES indicate that they are not vulnerable to RFDS.
Similarly, RFDS_CLEAR indicates that CPU is affected by RFDS, and has
the microcode to help mitigate RFDS.

Make RFDS_CLEAR and RFDS_NO bits available to guests.

Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
---
 target/i386/cpu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 9a210d8d9290..693a5e0fb2ce 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -1158,8 +1158,8 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
             NULL, "sbdr-ssdp-no", "fbsdp-no", "psdp-no",
             NULL, "fb-clear", NULL, NULL,
             NULL, NULL, NULL, NULL,
-            "pbrsb-no", NULL, "gds-no", NULL,
-            NULL, NULL, NULL, NULL,
+            "pbrsb-no", NULL, "gds-no", "rfds-no",
+            "rfds-clear", NULL, NULL, NULL,
         },
         .msr = {
             .index = MSR_IA32_ARCH_CAPABILITIES,

base-commit: a1932d7cd6507d4d9db2044a54731fff3e749bac
-- 
2.34.1



             reply	other threads:[~2024-03-13 14:54 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-03-13 14:53 Pawan Gupta [this message]
2024-03-15  7:50 ` [PATCH] target/i386: Export RFDS bit to guests Zhao Liu
2024-03-18  5:30   ` Pawan Gupta
2024-03-19  4:22 ` Xiaoyao Li
2024-03-19 15:08   ` Pawan Gupta
2024-03-20  0:23     ` Xiaoyao Li
2024-03-20  0:26       ` Pawan Gupta
2024-03-20 10:35 ` Paolo Bonzini

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