From 2308ee57d93d896618dd65c996429c9d3e469fe0 Mon Sep 17 00:00:00 2001 From: "Chang S. Bae" Date: Thu, 21 Oct 2021 15:55:27 -0700 Subject: [PATCH] x86/fpu/amx: Enable the AMX feature in 64-bit mode Add the AMX state components in XFEATURE_MASK_USER_SUPPORTED and the TILE_DATA component to the dynamic states and update the permission check table accordingly. This is only effective on 64 bit kernels as for 32bit kernels XFEATURE_MASK_TILE is defined as 0. TILE_DATA is caller-saved state and the only dynamic state. Add build time sanity check to ensure the assumption that every dynamic feature is caller- saved. Make AMX state depend on XFD as it is dynamic feature. Signed-off-by: Chang S. Bae Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov Link: https://lore.kernel.org/r/20211021225527.10184-24-chang.seok.bae@intel.com --- arch/x86/include/asm/fpu/xstate.h | 5 +++-- arch/x86/kernel/cpu/cpuid-deps.c | 1 + arch/x86/kernel/fpu/core.c | 6 ++++++ arch/x86/kernel/fpu/xstate.c | 5 +++-- 4 files changed, 13 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h index 10adf1376f0c..0f8b90ab18c9 100644 --- a/arch/x86/include/asm/fpu/xstate.h +++ b/arch/x86/include/asm/fpu/xstate.h @@ -35,7 +35,8 @@ XFEATURE_MASK_Hi16_ZMM | \ XFEATURE_MASK_PKRU | \ XFEATURE_MASK_BNDREGS | \ - XFEATURE_MASK_BNDCSR) + XFEATURE_MASK_BNDCSR | \ + XFEATURE_MASK_XTILE) /* * Features which are restored when returning to user space. @@ -46,7 +47,7 @@ (XFEATURE_MASK_USER_SUPPORTED & ~XFEATURE_MASK_PKRU) /* Features which are dynamically enabled for a process on request */ -#define XFEATURE_MASK_USER_DYNAMIC 0ULL +#define XFEATURE_MASK_USER_DYNAMIC XFEATURE_MASK_XTILE_DATA /* All currently supported supervisor features */ #define XFEATURE_MASK_SUPERVISOR_SUPPORTED (XFEATURE_MASK_PASID) diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c index d9ead9c20408..cb2fdd130aae 100644 --- a/arch/x86/kernel/cpu/cpuid-deps.c +++ b/arch/x86/kernel/cpu/cpuid-deps.c @@ -76,6 +76,7 @@ static const struct cpuid_dep cpuid_deps[] = { { X86_FEATURE_SGX1, X86_FEATURE_SGX }, { X86_FEATURE_SGX2, X86_FEATURE_SGX1 }, { X86_FEATURE_XFD, X86_FEATURE_XSAVES }, + { X86_FEATURE_AMX_TILE, X86_FEATURE_XFD }, {} }; diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 12ca174891dc..290836d1f2a7 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -495,6 +495,12 @@ int fpu_clone(struct task_struct *dst, unsigned long clone_flags) } /* + * If a new feature is added, ensure all dynamic features are + * caller-saved from here! + */ + BUILD_BUG_ON(XFEATURE_MASK_USER_DYNAMIC != XFEATURE_MASK_XTILE_DATA); + + /* * Save the default portion of the current FPU state into the * clone. Assume all dynamic features to be defined as caller- * saved, which enables skipping both the expansion of fpstate diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 987a07bc668b..d28829403ed0 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -404,7 +404,8 @@ static __init void os_xrstor_booting(struct xregs_state *xstate) XFEATURE_MASK_PKRU | \ XFEATURE_MASK_BNDREGS | \ XFEATURE_MASK_BNDCSR | \ - XFEATURE_MASK_PASID) + XFEATURE_MASK_PASID | \ + XFEATURE_MASK_XTILE) /* * setup the xstate image representing the init state @@ -1636,7 +1637,7 @@ static int __xstate_request_perm(u64 permitted, u64 requested) * Permissions array to map facilities with more than one component */ static const u64 xstate_prctl_req[XFEATURE_MAX] = { - /* [XFEATURE_XTILE_DATA] = XFEATURE_MASK_XTILE, */ + [XFEATURE_XTILE_DATA] = XFEATURE_MASK_XTILE_DATA, }; static int xstate_request_perm(unsigned long idx) -- 2.11.0