From: "tip-bot2 for Fenghua Yu" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Fenghua Yu <fenghua.yu@intel.com>, Borislav Petkov <bp@suse.de>,
Tony Luck <tony.luck@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [tip: x86/pasid] x86/traps: Demand-populate PASID MSR via #GP
Date: Tue, 15 Feb 2022 10:54:27 -0000 [thread overview]
Message-ID: <164492246742.16921.8526058476593067462.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20220207230254.3342514-9-fenghua.yu@intel.com>
The following commit has been merged into the x86/pasid branch of tip:
Commit-ID: fa6af69f38d3f409bedc55d0112eec36ed526d4b
Gitweb: https://git.kernel.org/tip/fa6af69f38d3f409bedc55d0112eec36ed526d4b
Author: Fenghua Yu <fenghua.yu@intel.com>
AuthorDate: Mon, 07 Feb 2022 15:02:51 -08:00
Committer: Borislav Petkov <bp@suse.de>
CommitterDate: Tue, 15 Feb 2022 11:31:43 +01:00
x86/traps: Demand-populate PASID MSR via #GP
All tasks start with PASID state disabled. This means that the first
time they execute an ENQCMD instruction they will take a #GP fault.
Modify the #GP fault handler to check if the "mm" for the task has
already been allocated a PASID. If so, try to fix the #GP fault by
loading the IA32_PASID MSR.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220207230254.3342514-9-fenghua.yu@intel.com
---
arch/x86/kernel/traps.c | 55 ++++++++++++++++++++++++++++++++++++++++-
1 file changed, 55 insertions(+)
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index c9d566d..7ef00de 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -39,6 +39,7 @@
#include <linux/io.h>
#include <linux/hardirq.h>
#include <linux/atomic.h>
+#include <linux/ioasid.h>
#include <asm/stacktrace.h>
#include <asm/processor.h>
@@ -559,6 +560,57 @@ static bool fixup_iopl_exception(struct pt_regs *regs)
return true;
}
+/*
+ * The unprivileged ENQCMD instruction generates #GPs if the
+ * IA32_PASID MSR has not been populated. If possible, populate
+ * the MSR from a PASID previously allocated to the mm.
+ */
+static bool try_fixup_enqcmd_gp(void)
+{
+#ifdef CONFIG_IOMMU_SVA
+ u32 pasid;
+
+ /*
+ * MSR_IA32_PASID is managed using XSAVE. Directly
+ * writing to the MSR is only possible when fpregs
+ * are valid and the fpstate is not. This is
+ * guaranteed when handling a userspace exception
+ * in *before* interrupts are re-enabled.
+ */
+ lockdep_assert_irqs_disabled();
+
+ /*
+ * Hardware without ENQCMD will not generate
+ * #GPs that can be fixed up here.
+ */
+ if (!cpu_feature_enabled(X86_FEATURE_ENQCMD))
+ return false;
+
+ pasid = current->mm->pasid;
+
+ /*
+ * If the mm has not been allocated a
+ * PASID, the #GP can not be fixed up.
+ */
+ if (!pasid_valid(pasid))
+ return false;
+
+ /*
+ * Did this thread already have its PASID activated?
+ * If so, the #GP must be from something else.
+ */
+ if (current->pasid_activated)
+ return false;
+
+ wrmsrl(MSR_IA32_PASID, pasid | MSR_IA32_PASID_VALID);
+ current->pasid_activated = 1;
+
+ return true;
+#else
+ return false;
+#endif
+}
+
DEFINE_IDTENTRY_ERRORCODE(exc_general_protection)
{
char desc[sizeof(GPFSTR) + 50 + 2*sizeof(unsigned long) + 1] = GPFSTR;
@@ -567,6 +619,9 @@ DEFINE_IDTENTRY_ERRORCODE(exc_general_protection)
unsigned long gp_addr;
int ret;
+ if (user_mode(regs) && try_fixup_enqcmd_gp())
+ return;
+
cond_local_irq_enable(regs);
if (static_cpu_has(X86_FEATURE_UMIP)) {
next prev parent reply other threads:[~2022-02-15 10:54 UTC|newest]
Thread overview: 214+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-07 23:02 [PATCH v4 00/11] Re-enable ENQCMD and PASID MSR Fenghua Yu
2022-02-07 23:02 ` Fenghua Yu
2022-02-07 23:02 ` [PATCH v4 01/11] iommu/sva: Rename CONFIG_IOMMU_SVA_LIB to CONFIG_IOMMU_SVA Fenghua Yu
2022-02-07 23:02 ` Fenghua Yu
2022-02-08 2:39 ` Lu Baolu
2022-02-08 2:39 ` Lu Baolu
2022-02-15 10:54 ` [tip: x86/pasid] " tip-bot2 for Fenghua Yu
2022-02-07 23:02 ` [PATCH v4 02/11] mm: Change CONFIG option for mm->pasid field Fenghua Yu
2022-02-07 23:02 ` Fenghua Yu
2022-02-08 2:40 ` Lu Baolu
2022-02-08 2:40 ` Lu Baolu
2022-02-15 10:54 ` [tip: x86/pasid] " tip-bot2 for Fenghua Yu
2022-02-07 23:02 ` [PATCH v4 03/11] iommu/ioasid: Introduce a helper to check for valid PASIDs Fenghua Yu
2022-02-07 23:02 ` Fenghua Yu
2022-02-08 2:40 ` Lu Baolu
2022-02-08 2:40 ` Lu Baolu
2022-02-15 10:54 ` [tip: x86/pasid] " tip-bot2 for Fenghua Yu
2022-02-07 23:02 ` [PATCH v4 04/11] kernel/fork: Initialize mm's PASID Fenghua Yu
2022-02-07 23:02 ` Fenghua Yu
2022-02-14 17:23 ` Thomas Gleixner
2022-02-14 17:23 ` Thomas Gleixner
2022-02-15 10:54 ` [tip: x86/pasid] " tip-bot2 for Fenghua Yu
2022-02-07 23:02 ` [PATCH v4 05/11] iommu/sva: Assign a PASID to mm on PASID allocation and free it on mm exit Fenghua Yu
2022-02-07 23:02 ` Fenghua Yu
2022-02-08 2:41 ` Lu Baolu
2022-02-08 2:41 ` Lu Baolu
2022-02-08 15:01 ` Fenghua Yu
2022-02-08 15:01 ` Fenghua Yu
2022-02-10 3:16 ` Jacob Pan
2022-02-10 3:16 ` Jacob Pan
2022-02-10 16:27 ` Fenghua Yu
2022-02-10 16:27 ` Fenghua Yu
2022-02-10 17:24 ` Luck, Tony
2022-02-10 17:24 ` Luck, Tony
2022-02-10 18:31 ` Fenghua Yu
2022-02-10 18:31 ` Fenghua Yu
2022-02-10 23:52 ` Fenghua Yu
2022-02-10 23:52 ` Fenghua Yu
2022-02-10 18:49 ` Jacob Pan
2022-02-10 18:49 ` Jacob Pan
2022-02-10 23:15 ` Fenghua Yu
2022-02-10 23:15 ` Fenghua Yu
2022-02-11 22:00 ` Dave Hansen
2022-02-11 22:00 ` Dave Hansen
2022-02-14 17:24 ` Thomas Gleixner
2022-02-14 17:24 ` Thomas Gleixner
2022-02-15 9:55 ` Joerg Roedel
2022-02-15 9:55 ` Joerg Roedel
2022-04-11 14:00 ` Zhangfei Gao
2022-04-11 14:10 ` Dave Hansen
2022-04-11 14:10 ` Dave Hansen
2022-04-11 14:20 ` zhangfei.gao
2022-04-11 14:20 ` zhangfei.gao
2022-04-11 14:36 ` Dave Hansen
2022-04-11 14:36 ` Dave Hansen
2022-04-11 14:44 ` zhangfei.gao
2022-04-11 14:44 ` zhangfei.gao
2022-04-11 14:52 ` Dave Hansen
2022-04-11 14:52 ` Dave Hansen
2022-04-11 15:13 ` zhangfei.gao
2022-04-11 15:13 ` zhangfei.gao
2022-04-12 7:04 ` zhangfei.gao
2022-04-12 7:04 ` zhangfei.gao
2022-04-12 13:41 ` Fenghua Yu
2022-04-12 13:41 ` Fenghua Yu
2022-04-12 14:39 ` Dave Hansen
2022-04-12 14:39 ` Dave Hansen
2022-04-15 9:59 ` Fenghua Yu
2022-04-15 9:59 ` Fenghua Yu
2022-04-12 15:35 ` zhangfei.gao
2022-04-12 15:35 ` zhangfei.gao
2022-04-14 10:08 ` zhangfei.gao
2022-04-14 10:08 ` zhangfei.gao
2022-04-15 9:51 ` Fenghua Yu
2022-04-15 9:51 ` Fenghua Yu
2022-04-15 10:14 ` zhangfei.gao
2022-04-15 10:14 ` zhangfei.gao
2022-04-15 10:14 ` zhangfei.gao
2022-04-15 10:50 ` Fenghua Yu
2022-04-15 10:50 ` Fenghua Yu
2022-04-15 11:52 ` zhangfei.gao
2022-04-15 11:52 ` zhangfei.gao
2022-04-15 12:37 ` Fenghua Yu
2022-04-15 12:37 ` Fenghua Yu
2022-04-16 1:30 ` zhangfei.gao
2022-04-16 1:30 ` zhangfei.gao
2022-04-15 19:07 ` Fenghua Yu
2022-04-15 19:07 ` Fenghua Yu
2022-04-15 21:00 ` Jacob Pan
2022-04-15 21:00 ` Jacob Pan
2022-04-16 1:43 ` zhangfei.gao
2022-04-16 1:43 ` zhangfei.gao
2022-04-18 18:14 ` Jacob Pan
2022-04-18 18:14 ` Jacob Pan
2022-04-19 1:02 ` zhangfei.gao
2022-04-19 1:02 ` zhangfei.gao
2022-04-18 6:34 ` Tian, Kevin
2022-04-18 6:34 ` Tian, Kevin
2022-04-18 18:11 ` Jacob Pan
2022-04-18 18:11 ` Jacob Pan
2022-04-20 16:45 ` Jean-Philippe Brucker
2022-04-20 16:45 ` Jean-Philippe Brucker
2022-04-21 6:47 ` zhangfei.gao
2022-04-21 6:47 ` zhangfei.gao
2022-04-22 9:03 ` zhangfei.gao
2022-04-22 9:03 ` zhangfei.gao
2022-04-22 10:11 ` Jean-Philippe Brucker
2022-04-22 10:11 ` Jean-Philippe Brucker
2022-04-22 13:15 ` zhangfei.gao
2022-04-22 13:15 ` zhangfei.gao
2022-04-22 15:50 ` Jean-Philippe Brucker
2022-04-22 15:50 ` Jean-Philippe Brucker
2022-04-23 11:13 ` zhangfei.gao
2022-04-23 11:13 ` zhangfei.gao
2022-04-24 2:58 ` Zhangfei Gao
2022-04-24 2:58 ` Zhangfei Gao
2022-04-24 9:52 ` Zhangfei Gao
2022-04-24 9:52 ` Zhangfei Gao
2022-04-25 13:53 ` Jean-Philippe Brucker
2022-04-25 13:53 ` Jean-Philippe Brucker
2022-04-25 14:18 ` Dave Hansen
2022-04-25 14:18 ` Dave Hansen
2022-04-25 14:26 ` Jean-Philippe Brucker
2022-04-25 14:26 ` Jean-Philippe Brucker
2022-04-25 15:34 ` Jacob Pan
2022-04-25 15:34 ` Jacob Pan
2022-04-25 16:13 ` Jean-Philippe Brucker
2022-04-25 16:13 ` Jean-Philippe Brucker
2022-04-25 22:32 ` Jacob Pan
2022-04-25 22:32 ` Jacob Pan
2022-04-26 4:20 ` Fenghua Yu
2022-04-26 4:20 ` Fenghua Yu
2022-04-26 5:04 ` Zhangfei Gao
2022-04-26 5:04 ` Zhangfei Gao
2022-04-28 0:54 ` Fenghua Yu
2022-04-28 0:54 ` Fenghua Yu
2022-04-28 8:43 ` Jean-Philippe Brucker
2022-04-28 8:43 ` Jean-Philippe Brucker
2022-04-28 15:09 ` Dave Hansen
2022-04-28 15:09 ` Dave Hansen
2022-04-28 15:28 ` Fenghua Yu
2022-04-28 15:28 ` Fenghua Yu
2022-04-28 15:42 ` Dave Hansen
2022-04-28 15:42 ` Dave Hansen
2022-04-28 16:01 ` Jean-Philippe Brucker
2022-04-28 16:01 ` Jean-Philippe Brucker
2022-04-28 16:35 ` Dave Hansen
2022-04-28 16:35 ` Dave Hansen
2022-04-26 4:28 ` Zhangfei Gao
2022-04-26 4:28 ` Zhangfei Gao
2022-04-26 4:36 ` Fenghua Yu
2022-04-26 4:36 ` Fenghua Yu
2022-04-26 5:19 ` Zhangfei Gao
2022-04-26 5:19 ` Zhangfei Gao
2022-04-25 15:55 ` Dave Hansen
2022-04-25 15:55 ` Dave Hansen
2022-04-25 16:40 ` Jean-Philippe Brucker
2022-04-25 16:40 ` Jean-Philippe Brucker
2022-04-26 15:27 ` Dave Hansen
2022-04-26 15:27 ` Dave Hansen
2022-04-26 16:48 ` Jean-Philippe Brucker
2022-04-26 16:48 ` Jean-Philippe Brucker
2022-04-26 23:31 ` Dave Hansen
2022-04-26 23:31 ` Dave Hansen
2022-04-28 8:39 ` Jean-Philippe Brucker
2022-04-28 8:39 ` Jean-Philippe Brucker
2022-04-29 7:53 ` Baolu Lu
2022-04-29 7:53 ` Baolu Lu
2022-04-29 13:51 ` Fenghua Yu
2022-04-29 13:51 ` Fenghua Yu
2022-04-29 14:34 ` Jean-Philippe Brucker
2022-04-29 14:34 ` Jean-Philippe Brucker
2022-04-29 22:19 ` Fenghua Yu
2022-04-29 22:19 ` Fenghua Yu
2022-04-30 7:33 ` Baolu Lu
2022-04-30 7:33 ` Baolu Lu
2022-05-03 7:49 ` Jean-Philippe Brucker
2022-05-03 7:49 ` Jean-Philippe Brucker
2022-05-06 5:36 ` Baolu Lu
2022-05-06 5:36 ` Baolu Lu
2022-04-12 14:36 ` Dave Hansen
2022-04-12 14:36 ` Dave Hansen
2022-04-12 15:10 ` Jean-Philippe Brucker
2022-04-12 15:10 ` Jean-Philippe Brucker
2022-04-12 15:35 ` Dave Hansen
2022-04-12 15:35 ` Dave Hansen
2022-04-13 11:14 ` Lu Baolu
2022-04-13 11:14 ` Lu Baolu
2022-04-25 2:57 ` zhangfei.gao
2022-04-25 2:57 ` zhangfei.gao
2022-02-15 10:54 ` [tip: x86/pasid] " tip-bot2 for Fenghua Yu
2022-02-07 23:02 ` [PATCH v4 06/11] x86/fpu: Clear PASID when copying fpstate Fenghua Yu
2022-02-07 23:02 ` Fenghua Yu
2022-02-15 10:54 ` [tip: x86/pasid] " tip-bot2 for Fenghua Yu
2022-02-07 23:02 ` [PATCH v4 07/11] sched: Define and initialize a flag to identify valid PASID in the task Fenghua Yu
2022-02-07 23:02 ` Fenghua Yu
2022-02-15 10:54 ` [tip: x86/pasid] " tip-bot2 for Peter Zijlstra
2022-02-07 23:02 ` [PATCH v4 08/11] x86/traps: Demand-populate PASID MSR via #GP Fenghua Yu
2022-02-07 23:02 ` Fenghua Yu
2022-02-15 10:54 ` tip-bot2 for Fenghua Yu [this message]
2022-02-07 23:02 ` [PATCH v4 09/11] x86/cpufeatures: Re-enable ENQCMD Fenghua Yu
2022-02-07 23:02 ` Fenghua Yu
2022-02-15 10:54 ` [tip: x86/pasid] " tip-bot2 for Fenghua Yu
2022-02-07 23:02 ` [PATCH v4 10/11] tools/objtool: Check for use of the ENQCMD instruction in the kernel Fenghua Yu
2022-02-07 23:02 ` Fenghua Yu
2022-02-15 10:54 ` [tip: x86/pasid] " tip-bot2 for Fenghua Yu
2022-03-09 7:55 ` [tip: x86/core] " tip-bot2 for Fenghua Yu
2022-03-15 10:44 ` tip-bot2 for Fenghua Yu
2022-02-07 23:02 ` [PATCH v4 11/11] docs: x86: Change documentation for SVA (Shared Virtual Addressing) Fenghua Yu
2022-02-07 23:02 ` Fenghua Yu
2022-02-14 17:25 ` Thomas Gleixner
2022-02-14 17:25 ` Thomas Gleixner
2022-02-15 10:54 ` [tip: x86/pasid] Documentation/x86: Update " tip-bot2 for Fenghua Yu
2022-02-11 20:04 ` [PATCH v4 00/11] Re-enable ENQCMD and PASID MSR Fenghua Yu
2022-02-11 20:04 ` Fenghua Yu
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