From: "Chang S. Bae" <chang.seok.bae@intel.com>
To: bp@suse.de, luto@kernel.org, tglx@linutronix.de,
mingo@kernel.org, x86@kernel.org
Cc: len.brown@intel.com, dave.hansen@intel.com, jing2.liu@intel.com,
ravi.v.shankar@intel.com, linux-kernel@vger.kernel.org,
chang.seok.bae@intel.com
Subject: [PATCH v6 04/26] x86/fpu/xstate: Add a new variable to indicate dynamic user states
Date: Tue, 29 Jun 2021 23:02:04 -0700 [thread overview]
Message-ID: <20210630060226.24652-5-chang.seok.bae@intel.com> (raw)
In-Reply-To: <20210630060226.24652-1-chang.seok.bae@intel.com>
The XSTATE per-task buffer is in preparation to be dynamic for user states.
Introduce a new mask variable to indicate the 'dynamic' user states. The
value is determined at boot-time.
No functional change.
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Reviewed-by: Len Brown <len.brown@intel.com>
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
---
Changes from v5:
* Made the variable __ro_after_init.
* Dropped the perf's xstate buffer renaming, as renamed already.
Changes from v3:
* Updated the changelog. (Borislav Petkov)
* Updated the code comment. (Borislav Petkov)
Changes from v2:
* Updated the changelog for clarification.
---
arch/x86/include/asm/fpu/xstate.h | 2 ++
arch/x86/kernel/fpu/xstate.c | 9 +++++++++
2 files changed, 11 insertions(+)
diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h
index 2451bccc6cac..bc4cba62906b 100644
--- a/arch/x86/include/asm/fpu/xstate.h
+++ b/arch/x86/include/asm/fpu/xstate.h
@@ -129,6 +129,8 @@ static inline u64 xfeatures_mask_independent(void)
return XFEATURE_MASK_INDEPENDENT;
}
+extern u64 xfeatures_mask_user_dynamic;
+
extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
extern void __init update_regset_xstate_info(unsigned int size,
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index af2adc954578..1d76afc29f19 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -62,6 +62,12 @@ static short xsave_cpuid_features[] __initdata = {
u64 xfeatures_mask_all __ro_after_init;
EXPORT_SYMBOL_GPL(xfeatures_mask_all);
+/*
+ * This represents user xstates, a subset of xfeatures_mask_all, saved in a
+ * dynamic kernel XSAVE buffer.
+ */
+u64 xfeatures_mask_user_dynamic __ro_after_init;
+
static unsigned int xstate_offsets[XFEATURE_MAX] __ro_after_init =
{ [ 0 ... XFEATURE_MAX - 1] = -1};
static unsigned int xstate_sizes[XFEATURE_MAX] __ro_after_init =
@@ -709,6 +715,7 @@ static int __init init_xstate_size(void)
static void fpu__init_disable_system_xstate(void)
{
xfeatures_mask_all = 0;
+ xfeatures_mask_user_dynamic = 0;
cr4_clear_bits(X86_CR4_OSXSAVE);
setup_clear_cpu_cap(X86_FEATURE_XSAVE);
}
@@ -780,6 +787,8 @@ void __init fpu__init_system_xstate(void)
/* Store it for paranoia check at the end */
xfeatures = xfeatures_mask_all;
+ /* Do not support the dynamically allocated buffer yet. */
+ xfeatures_mask_user_dynamic = 0;
/* Enable xstate instructions to be able to continue with initialization: */
fpu__init_cpu_xstate();
--
2.17.1
next prev parent reply other threads:[~2021-06-30 6:08 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-30 6:02 [PATCH v6 00/26] x86: Support Intel Advanced Matrix Extensions Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 01/26] x86/fpu/xstate: Modify the initialization helper to handle both static and dynamic buffers Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 02/26] x86/fpu/xstate: Modify state copy helpers " Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 03/26] x86/fpu/xstate: Modify address finders " Chang S. Bae
2021-06-30 6:02 ` Chang S. Bae [this message]
2021-06-30 6:02 ` [PATCH v6 05/26] x86/fpu/xstate: Add new variables to indicate dynamic XSTATE buffer size Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 06/26] x86/fpu/xstate: Calculate and remember dynamic XSTATE buffer sizes Chang S. Bae
2021-07-02 15:19 ` Bae, Chang Seok
2021-07-02 15:17 ` [PATCH v6-fix " Chang S. Bae
2021-07-02 17:46 ` Dave Hansen
2021-06-30 6:02 ` [PATCH v6 07/26] x86/fpu/xstate: Convert the struct fpu 'state' field to a pointer Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 08/26] x86/fpu/xstate: Introduce helpers to manage the XSTATE buffer dynamically Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 09/26] x86/fpu/xstate: Update the XSTATE save function to support dynamic states Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 10/26] x86/fpu/xstate: Update the XSTATE buffer address finder " Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 11/26] x86/fpu/xstate: Update the XSTATE context copy function " Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 12/26] x86/fpu/xstate: Use feature disable (XFD) to protect dynamic user state Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 13/26] x86/fpu/xstate: Support ptracer-induced XSTATE buffer expansion Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 14/26] x86/arch_prctl: Create ARCH_ENABLE_XSTATE Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 15/26] x86/fpu/xstate: Support both legacy and expanded signal XSTATE size Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 16/26] x86/fpu/xstate: Adjust the XSAVE feature table to address gaps in state component numbers Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 17/26] x86/fpu/xstate: Disable XSTATE support if an inconsistent state is detected Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 18/26] x86/cpufeatures/amx: Enumerate Advanced Matrix Extension (AMX) feature bits Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 19/26] x86/fpu/amx: Define AMX state components and have it used for boot-time checks Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 20/26] x86/fpu/amx: Initialize child's AMX state Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 21/26] x86/fpu/amx: Enable the AMX feature in 64-bit mode Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 22/26] x86/fpu/xstate: Skip writing zeros to signal frame for dynamic user states if in INIT-state Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 23/26] selftest/x86/amx: Test cases for the AMX state management Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 24/26] x86/insn/amx: Add TILERELEASE instruction to the opcode map Chang S. Bae
2021-06-30 6:02 ` [PATCH v6 25/26] intel_idle/amx: Clear the AMX state before entering idle Chang S. Bae
2021-06-30 13:11 ` Rafael J. Wysocki
2021-06-30 6:02 ` [PATCH v6 26/26] x86/fpu/xstate: Add a sanity check for XFD state when saving XSTATE Chang S. Bae
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