[v1] First batch of i386 and build system patch for QEMU 9.1

[PULL 28/63] target/i386: Export RFDS bit to guests

Paolo Bonzini posted 63 patches 1 year, 9 months ago

Diff against v2
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Maintainers: Paolo Bonzini <pbonzini@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, David Hildenbrand <david@redhat.com>, Igor Mammedov <imammedo@redhat.com>, Jason Wang <jasowang@redhat.com>, Andrew Melnychenko <andrew@daynix.com>, Yuri Benditovich <yuri.benditovich@daynix.com>, Peter Maydell <peter.maydell@linaro.org>, Eduardo Habkost <eduardo@habkost.net>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Yanan Wang <wangyanan55@huawei.com>, Gerd Hoffmann <kraxel@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>, Laurent Vivier <laurent@vivier.eu>, Nicholas Piggin <npiggin@gmail.com>, Daniel Henrique Barboza <danielhb413@gmail.com>, David Gibson <david@gibson.dropbear.id.au>, Harsh Prateek Bora <harshpb@linux.ibm.com>, Ilya Leoshkevich <iii@linux.ibm.com>, Thomas Huth <thuth@redhat.com>, Halil Pasic <pasic@linux.ibm.com>, Christian Borntraeger <borntraeger@linux.ibm.com>, Eric Farman <farman@linux.ibm.com>, Peter Xu <peterx@redhat.com>, Cornelia Huck <cohuck@redhat.com>, "Marc-André Lureau" <marcandre.lureau@redhat.com>, "Daniel P. Berrangé" <berrange@redhat.com>, Fabiano Rosas <farosas@suse.de>, Eric Blake <eblake@redhat.com>, Markus Armbruster <armbru@redhat.com>, "Alex Bennée" <alex.bennee@linaro.org>, Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>, Marcelo Tosatti <mtosatti@redhat.com>, Song Gao <gaosong@loongson.cn>, Huacai Chen <chenhuacai@kernel.org>, Aurelien Jarno <aurelien@aurel32.net>, Jiaxun Yang <jiaxun.yang@flygoat.com>, Aleksandar Rikalo <aleksandar.rikalo@syrmia.com>, Palmer Dabbelt <palmer@dabbelt.com>, Alistair Francis <alistair.francis@wdc.com>, Bin Meng <bin.meng@windriver.com>, Weiwei Li <liwei1518@gmail.com>, Liu Zhiwei <zhiwei_liu@linux.alibaba.com>

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[PULL 28/63] target/i386: Export RFDS bit to guests

Posted by Paolo Bonzini 1 year, 9 months ago

From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>

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>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Message-ID: <9a38877857392b5c2deae7e7db1b170d15510314.1710341348.git.pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.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 c295491d8ae..eda15b0d4c7 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,
-- 
2.44.0