From: Suraj Jitindar Singh <surajjs@amazon.com>
To: <stable@vger.kernel.org>
Cc: <surajjs@amazon.com>, <sjitindarsingh@gmail.com>,
<cascardo@canonical.com>, <kvm@vger.kernel.org>,
<pbonzini@redhat.com>, <jpoimboe@kernel.org>,
<peterz@infradead.org>, <x86@kernel.org>
Subject: [PATCH 4.14 23/34] x86/speculation: Use cached host SPEC_CTRL value for guest entry/exit
Date: Thu, 27 Oct 2022 13:55:22 -0700 [thread overview]
Message-ID: <20221027205523.17741-3-surajjs@amazon.com> (raw)
In-Reply-To: <20221027205523.17741-1-surajjs@amazon.com>
From: Josh Poimboeuf <jpoimboe@kernel.org>
commit bbb69e8bee1bd882784947095ffb2bfe0f7c9470 upstream.
There's no need to recalculate the host value for every entry/exit.
Just use the cached value in spec_ctrl_current().
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/kernel/cpu/bugs.c | 12 +-----------
1 file changed, 1 insertion(+), 11 deletions(-)
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 31aa473717bb..a0d180e52231 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -198,7 +198,7 @@ void __init check_bugs(void)
void
x86_virt_spec_ctrl(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl, bool setguest)
{
- u64 msrval, guestval, hostval = x86_spec_ctrl_base;
+ u64 msrval, guestval, hostval = spec_ctrl_current();
struct thread_info *ti = current_thread_info();
/* Is MSR_SPEC_CTRL implemented ? */
@@ -211,15 +211,6 @@ x86_virt_spec_ctrl(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl, bool setguest)
guestval = hostval & ~x86_spec_ctrl_mask;
guestval |= guest_spec_ctrl & x86_spec_ctrl_mask;
- /* SSBD controlled in MSR_SPEC_CTRL */
- if (static_cpu_has(X86_FEATURE_SPEC_CTRL_SSBD) ||
- static_cpu_has(X86_FEATURE_AMD_SSBD))
- hostval |= ssbd_tif_to_spec_ctrl(ti->flags);
-
- /* Conditional STIBP enabled? */
- if (static_branch_unlikely(&switch_to_cond_stibp))
- hostval |= stibp_tif_to_spec_ctrl(ti->flags);
-
if (hostval != guestval) {
msrval = setguest ? guestval : hostval;
wrmsrl(MSR_IA32_SPEC_CTRL, msrval);
@@ -1272,7 +1263,6 @@ static void __init spectre_v2_select_mitigation(void)
pr_err(SPECTRE_V2_EIBRS_EBPF_MSG);
if (spectre_v2_in_ibrs_mode(mode)) {
- /* Force it so VMEXIT will restore correctly */
x86_spec_ctrl_base |= SPEC_CTRL_IBRS;
write_spec_ctrl_current(x86_spec_ctrl_base, true);
}
--
2.17.1
next prev parent reply other threads:[~2022-10-27 21:03 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-27 20:48 [PATCH 4.14 00/34] Retbleed & PBRSB Mitigations Suraj Jitindar Singh
2022-10-27 20:54 ` [PATCH 4.14 01/34] Revert "x86/cpu: Add a steppings field to struct x86_cpu_id" Suraj Jitindar Singh
2022-10-27 20:54 ` [PATCH 4.14 02/34] x86/cpufeature: Add facility to check for min microcode revisions Suraj Jitindar Singh
2022-10-27 20:54 ` [PATCH 4.14 03/34] x86/cpufeature: Fix various quality problems in the <asm/cpu_device_hd.h> header Suraj Jitindar Singh
2022-10-27 20:54 ` [PATCH 4.14 04/34] x86/devicetable: Move x86 specific macro out of generic code Suraj Jitindar Singh
2022-10-27 20:54 ` [PATCH 4.14 05/34] x86/cpu: Add consistent CPU match macros Suraj Jitindar Singh
2022-10-27 20:54 ` [PATCH 4.14 06/34] x86/cpu: Add a steppings field to struct x86_cpu_id Suraj Jitindar Singh
2022-10-27 20:54 ` [PATCH 4.14 07/34] x86/entry: Remove skip_r11rcx Suraj Jitindar Singh
2022-10-27 20:54 ` [PATCH 4.14 08/34] x86/cpufeatures: Move RETPOLINE flags to word 11 Suraj Jitindar Singh
2022-10-27 20:54 ` [PATCH 4.14 09/34] x86/bugs: Report AMD retbleed vulnerability Suraj Jitindar Singh
2022-10-27 20:54 ` [PATCH 4.14 10/34] x86/bugs: Add AMD retbleed= boot parameter Suraj Jitindar Singh
2022-10-27 20:54 ` [PATCH 4.14 11/34] x86/bugs: Keep a per-CPU IA32_SPEC_CTRL value Suraj Jitindar Singh
2022-10-27 20:54 ` [PATCH 4.14 12/34] x86/entry: Add kernel IBRS implementation Suraj Jitindar Singh
2022-10-27 20:54 ` [PATCH 4.14 13/34] x86/bugs: Optimize SPEC_CTRL MSR writes Suraj Jitindar Singh
2022-10-27 20:55 ` [PATCH 4.14 14/34] x86/speculation: Add spectre_v2=ibrs option to support Kernel IBRS Suraj Jitindar Singh
2022-10-27 20:55 ` [PATCH 4.14 15/34] x86/bugs: Split spectre_v2_select_mitigation() and spectre_v2_user_select_mitigation() Suraj Jitindar Singh
2022-10-27 20:55 ` [PATCH 4.14 16/34] x86/bugs: Report Intel retbleed vulnerability Suraj Jitindar Singh
2022-10-27 20:55 ` [PATCH 4.14 17/34] entel_idle: Disable IBRS during long idle Suraj Jitindar Singh
2022-10-27 20:55 ` [PATCH 4.14 18/34] x86/speculation: Change FILL_RETURN_BUFFER to work with objtool Suraj Jitindar Singh
2022-10-27 20:55 ` [PATCH 4.14 19/34] x86/speculation: Add LFENCE to RSB fill sequence Suraj Jitindar Singh
2022-10-27 20:55 ` [PATCH 4.14 20/34] x86/speculation: Fix RSB filling with CONFIG_RETPOLINE=n Suraj Jitindar Singh
2022-10-27 20:55 ` [PATCH 4.14 21/34] x86/speculation: Fix firmware entry SPEC_CTRL handling Suraj Jitindar Singh
2022-10-27 20:55 ` [PATCH 4.14 22/34] x86/speculation: Fix SPEC_CTRL write on SMT state change Suraj Jitindar Singh
2022-10-27 20:55 ` Suraj Jitindar Singh [this message]
2022-10-27 20:55 ` [PATCH 4.14 24/34] x86/speculation: Remove x86_spec_ctrl_mask Suraj Jitindar Singh
2022-10-27 20:55 ` [PATCH 4.14 25/34] KVM: VMX: Prevent guest RSB poisoning attacks with eIBRS Suraj Jitindar Singh
2022-10-27 20:55 ` [PATCH 4.14 26/34] KVM: VMX: Fix IBRS handling after vmexit Suraj Jitindar Singh
2022-10-27 20:55 ` [PATCH 4.14 27/34] x86/speculation: Fill RSB on vmexit for IBRS Suraj Jitindar Singh
2022-10-27 20:55 ` [PATCH 4.14 28/34] x86/common: Stamp out the stepping madness Suraj Jitindar Singh
2022-10-27 20:55 ` [PATCH 4.14 29/34] x86/cpu/amd: Enumerate BTC_NO Suraj Jitindar Singh
2022-10-27 20:55 ` [PATCH 4.14 30/34] x86/bugs: Add Cannon lake to RETBleed affected CPU list Suraj Jitindar Singh
2022-10-27 20:55 ` [PATCH 4.14 31/34] x86/speculation: Disable RRSBA behavior Suraj Jitindar Singh
2022-10-27 20:55 ` [PATCH 4.14 32/34] x86/speculation: Use DECLARE_PER_CPU for x86_spec_ctrl_current Suraj Jitindar Singh
2022-10-27 20:56 ` [PATCH 4.14 33/34] x86/bugs: Warn when "ibrs" mitigation is selected on Enhanced IBRS parts Suraj Jitindar Singh
2022-10-27 20:56 ` [PATCH 4.14 34/34] x86/speculation: Add RSB VM Exit protections Suraj Jitindar Singh
2022-10-31 7:00 ` [PATCH 4.14 00/34] Retbleed & PBRSB Mitigations Greg KH
-- strict thread matches above, loose matches on Subject: below --
2022-10-31 7:02 [PATCH 4.14 00/34] 4.14.297-rc1 review Greg Kroah-Hartman
2022-10-31 7:02 ` [PATCH 4.14 23/34] x86/speculation: Use cached host SPEC_CTRL value for guest entry/exit Greg Kroah-Hartman
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