diff options
Diffstat (limited to 'debian/patches/bugfix/x86/x86-mmio-Disable-KVM-mitigation-when-X86_FEATURE_CLE.patch')
| -rw-r--r-- | debian/patches/bugfix/x86/x86-mmio-Disable-KVM-mitigation-when-X86_FEATURE_CLE.patch | 58 |
1 files changed, 0 insertions, 58 deletions
diff --git a/debian/patches/bugfix/x86/x86-mmio-Disable-KVM-mitigation-when-X86_FEATURE_CLE.patch b/debian/patches/bugfix/x86/x86-mmio-Disable-KVM-mitigation-when-X86_FEATURE_CLE.patch deleted file mode 100644 index 313064d2bc..0000000000 --- a/debian/patches/bugfix/x86/x86-mmio-Disable-KVM-mitigation-when-X86_FEATURE_CLE.patch +++ /dev/null @@ -1,58 +0,0 @@ -From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> -Date: Mon, 11 Mar 2024 12:29:43 -0700 -Subject: x86/mmio: Disable KVM mitigation when X86_FEATURE_CLEAR_CPU_BUF is - set -Origin: https://git.kernel.org/linus/e95df4ec0c0c9791941f112db699fae794b9862a - -Currently MMIO Stale Data mitigation for CPUs not affected by MDS/TAA is -to only deploy VERW at VMentry by enabling mmio_stale_data_clear static -branch. No mitigation is needed for kernel->user transitions. If such -CPUs are also affected by RFDS, its mitigation may set -X86_FEATURE_CLEAR_CPU_BUF to deploy VERW at kernel->user and VMentry. -This could result in duplicate VERW at VMentry. - -Fix this by disabling mmio_stale_data_clear static branch when -X86_FEATURE_CLEAR_CPU_BUF is enabled. - -Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> -Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> -Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> ---- - arch/x86/kernel/cpu/bugs.c | 14 ++++++++++++-- - 1 file changed, 12 insertions(+), 2 deletions(-) - -diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c -index 48d049cd74e7..cd6ac89c1a0d 100644 ---- a/arch/x86/kernel/cpu/bugs.c -+++ b/arch/x86/kernel/cpu/bugs.c -@@ -422,6 +422,13 @@ static void __init mmio_select_mitigation(void) - if (boot_cpu_has_bug(X86_BUG_MDS) || (boot_cpu_has_bug(X86_BUG_TAA) && - boot_cpu_has(X86_FEATURE_RTM))) - setup_force_cpu_cap(X86_FEATURE_CLEAR_CPU_BUF); -+ -+ /* -+ * X86_FEATURE_CLEAR_CPU_BUF could be enabled by other VERW based -+ * mitigations, disable KVM-only mitigation in that case. -+ */ -+ if (boot_cpu_has(X86_FEATURE_CLEAR_CPU_BUF)) -+ static_branch_disable(&mmio_stale_data_clear); - else - static_branch_enable(&mmio_stale_data_clear); - -@@ -498,8 +505,11 @@ static void __init md_clear_update_mitigation(void) - taa_mitigation = TAA_MITIGATION_VERW; - taa_select_mitigation(); - } -- if (mmio_mitigation == MMIO_MITIGATION_OFF && -- boot_cpu_has_bug(X86_BUG_MMIO_STALE_DATA)) { -+ /* -+ * MMIO_MITIGATION_OFF is not checked here so that mmio_stale_data_clear -+ * gets updated correctly as per X86_FEATURE_CLEAR_CPU_BUF state. -+ */ -+ if (boot_cpu_has_bug(X86_BUG_MMIO_STALE_DATA)) { - mmio_mitigation = MMIO_MITIGATION_VERW; - mmio_select_mitigation(); - } --- -2.43.0 - |