x86/fpu: Move xstate feature masks to fpu_*_cfg

Move the feature mask storage to the kernel and user config
structs. Default and maximum feature set are the same for now.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211014230739.352041752@linutronix.de

diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h
index 61fcb15..fe7c9af 100644 (file)
--- a/arch/x86/include/asm/fpu/xstate.h
+++ b/arch/x86/include/asm/fpu/xstate.h
@@ -78,11 +78,9 @@
                                      XFEATURE_MASK_INDEPENDENT | \
                                      XFEATURE_MASK_SUPERVISOR_UNSUPPORTED)
 
-extern u64 xfeatures_mask_all;
-
 static inline u64 xfeatures_mask_supervisor(void)
 {
-       return xfeatures_mask_all & XFEATURE_MASK_SUPERVISOR_SUPPORTED;
+       return fpu_kernel_cfg.max_features & XFEATURE_MASK_SUPERVISOR_SUPPORTED;
 }
 
 /*
@@ -91,7 +89,7 @@ static inline u64 xfeatures_mask_supervisor(void)
  */
 static inline u64 xfeatures_mask_uabi(void)
 {
-       return xfeatures_mask_all & XFEATURE_MASK_USER_SUPPORTED;
+       return fpu_kernel_cfg.max_features & XFEATURE_MASK_USER_SUPPORTED;
 }
 
 /*
@@ -102,7 +100,7 @@ static inline u64 xfeatures_mask_uabi(void)
  */
 static inline u64 xfeatures_mask_restore_user(void)
 {
-       return xfeatures_mask_all & XFEATURE_MASK_USER_RESTORE;
+       return fpu_kernel_cfg.max_features & XFEATURE_MASK_USER_RESTORE;
 }
 
 /*
@@ -111,7 +109,7 @@ static inline u64 xfeatures_mask_restore_user(void)
  */
 static inline u64 xfeatures_mask_fpstate(void)
 {
-       return xfeatures_mask_all & \
+       return fpu_kernel_cfg.max_features & \
                (XFEATURE_MASK_USER_RESTORE | XFEATURE_MASK_SUPERVISOR_SUPPORTED);
 }
 

diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 69abf3a..501e21c 100644 (file)
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -349,8 +349,8 @@ void fpstate_reset(struct fpu *fpu)
        /* Initialize sizes and feature masks */
        fpu->fpstate->size              = fpu_kernel_cfg.default_size;
        fpu->fpstate->user_size         = fpu_user_cfg.default_size;
-       fpu->fpstate->xfeatures         = xfeatures_mask_all;
-       fpu->fpstate->user_xfeatures    = xfeatures_mask_uabi();
+       fpu->fpstate->xfeatures         = fpu_kernel_cfg.default_features;
+       fpu->fpstate->user_xfeatures    = fpu_user_cfg.default_features;
 }
 
 #if IS_ENABLED(CONFIG_KVM)

diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c
index 58043ed..7074154 100644 (file)
--- a/arch/x86/kernel/fpu/init.c
+++ b/arch/x86/kernel/fpu/init.c
@@ -211,7 +211,7 @@ static void __init fpu__init_init_fpstate(void)
 {
        /* Bring init_fpstate size and features up to date */
        init_fpstate.size               = fpu_kernel_cfg.max_size;
-       init_fpstate.xfeatures          = xfeatures_mask_all;
+       init_fpstate.xfeatures          = fpu_kernel_cfg.max_features;
 }
 
 /*

diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
index fab4403..c14f477 100644 (file)
--- a/arch/x86/kernel/fpu/signal.c
+++ b/arch/x86/kernel/fpu/signal.c
@@ -417,7 +417,8 @@ static bool __fpu_restore_sig(void __user *buf, void __user *buf_fx,
                u64 mask = user_xfeatures | xfeatures_mask_supervisor();
 
                fpregs->xsave.header.xfeatures &= mask;
-               success = !os_xrstor_safe(&fpregs->xsave, xfeatures_mask_all);
+               success = !os_xrstor_safe(&fpregs->xsave,
+                                         fpu_kernel_cfg.max_features);
        } else {
                success = !fxrstor_safe(&fpregs->fxsave);
        }

diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 94f5e37..8b496c0 100644 (file)
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -62,12 +62,6 @@ static short xsave_cpuid_features[] __initdata = {
        X86_FEATURE_ENQCMD,
 };
 
-/*
- * This represents the full set of bits that should ever be set in a kernel
- * XSAVE buffer, both supervisor and user xstates.
- */
-u64 xfeatures_mask_all __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 =
@@ -84,7 +78,7 @@ static unsigned int xstate_supervisor_only_offsets[XFEATURE_MAX] __ro_after_init
  */
 int cpu_has_xfeatures(u64 xfeatures_needed, const char **feature_name)
 {
-       u64 xfeatures_missing = xfeatures_needed & ~xfeatures_mask_all;
+       u64 xfeatures_missing = xfeatures_needed & ~fpu_kernel_cfg.max_features;
 
        if (unlikely(feature_name)) {
                long xfeature_idx, max_idx;
@@ -134,7 +128,7 @@ static bool xfeature_is_supervisor(int xfeature_nr)
  */
 void fpu__init_cpu_xstate(void)
 {
-       if (!boot_cpu_has(X86_FEATURE_XSAVE) || !xfeatures_mask_all)
+       if (!boot_cpu_has(X86_FEATURE_XSAVE) || !fpu_kernel_cfg.max_features)
                return;
 
        cr4_set_bits(X86_CR4_OSXSAVE);
@@ -144,7 +138,7 @@ void fpu__init_cpu_xstate(void)
         * managed by XSAVE{C, OPT, S} and XRSTOR{S}.  Only XSAVE user
         * states can be set here.
         */
-       xsetbv(XCR_XFEATURE_ENABLED_MASK, xfeatures_mask_uabi());
+       xsetbv(XCR_XFEATURE_ENABLED_MASK, fpu_user_cfg.max_features);
 
        /*
         * MSR_IA32_XSS sets supervisor states managed by XSAVES.
@@ -157,7 +151,7 @@ void fpu__init_cpu_xstate(void)
 
 static bool xfeature_enabled(enum xfeature xfeature)
 {
-       return xfeatures_mask_all & BIT_ULL(xfeature);
+       return fpu_kernel_cfg.max_features & BIT_ULL(xfeature);
 }
 
 /*
@@ -183,7 +177,7 @@ static void __init setup_xstate_features(void)
        xstate_sizes[XFEATURE_SSE]      = sizeof_field(struct fxregs_state,
                                                       xmm_space);
 
-       for_each_extended_xfeature(i, xfeatures_mask_all) {
+       for_each_extended_xfeature(i, fpu_kernel_cfg.max_features) {
                cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx);
 
                xstate_sizes[i] = eax;
@@ -288,14 +282,14 @@ static void __init setup_xstate_comp_offsets(void)
                                                     xmm_space);
 
        if (!cpu_feature_enabled(X86_FEATURE_XSAVES)) {
-               for_each_extended_xfeature(i, xfeatures_mask_all)
+               for_each_extended_xfeature(i, fpu_kernel_cfg.max_features)
                        xstate_comp_offsets[i] = xstate_offsets[i];
                return;
        }
 
        next_offset = FXSAVE_SIZE + XSAVE_HDR_SIZE;
 
-       for_each_extended_xfeature(i, xfeatures_mask_all) {
+       for_each_extended_xfeature(i, fpu_kernel_cfg.max_features) {
                if (xfeature_is_aligned(i))
                        next_offset = ALIGN(next_offset, 64);
 
@@ -319,7 +313,7 @@ static void __init setup_supervisor_only_offsets(void)
 
        next_offset = FXSAVE_SIZE + XSAVE_HDR_SIZE;
 
-       for_each_extended_xfeature(i, xfeatures_mask_all) {
+       for_each_extended_xfeature(i, fpu_kernel_cfg.max_features) {
                if (!xfeature_is_supervisor(i))
                        continue;
 
@@ -338,7 +332,7 @@ static void __init print_xstate_offset_size(void)
 {
        int i;
 
-       for_each_extended_xfeature(i, xfeatures_mask_all) {
+       for_each_extended_xfeature(i, fpu_kernel_cfg.max_features) {
                pr_info("x86/fpu: xstate_offset[%d]: %4d, xstate_sizes[%d]: %4d\n",
                         i, xstate_comp_offsets[i], i, xstate_sizes[i]);
        }
@@ -401,7 +395,7 @@ static void __init setup_init_fpu_buf(void)
        setup_xstate_features();
        print_xstate_features();
 
-       xstate_init_xcomp_bv(&init_fpstate.regs.xsave, xfeatures_mask_all);
+       xstate_init_xcomp_bv(&init_fpstate.regs.xsave, fpu_kernel_cfg.max_features);
 
        /*
         * Init all the features state with header.xfeatures being 0x0
@@ -570,7 +564,7 @@ static bool __init paranoid_xstate_size_valid(unsigned int kernel_size)
        unsigned int size = FXSAVE_SIZE + XSAVE_HDR_SIZE;
        int i;
 
-       for_each_extended_xfeature(i, xfeatures_mask_all) {
+       for_each_extended_xfeature(i, fpu_kernel_cfg.max_features) {
                if (!check_xstate_against_struct(i))
                        return false;
                /*
@@ -724,7 +718,7 @@ static int __init init_xstate_size(void)
  */
 static void __init fpu__init_disable_system_xstate(unsigned int legacy_size)
 {
-       xfeatures_mask_all = 0;
+       fpu_kernel_cfg.max_features = 0;
        cr4_clear_bits(X86_CR4_OSXSAVE);
        setup_clear_cpu_cap(X86_FEATURE_XSAVE);
 
@@ -768,13 +762,13 @@ void __init fpu__init_system_xstate(unsigned int legacy_size)
         * Find user xstates supported by the processor.
         */
        cpuid_count(XSTATE_CPUID, 0, &eax, &ebx, &ecx, &edx);
-       xfeatures_mask_all = eax + ((u64)edx << 32);
+       fpu_kernel_cfg.max_features = eax + ((u64)edx << 32);
 
        /*
         * Find supervisor xstates supported by the processor.
         */
        cpuid_count(XSTATE_CPUID, 1, &eax, &ebx, &ecx, &edx);
-       xfeatures_mask_all |= ecx + ((u64)edx << 32);
+       fpu_kernel_cfg.max_features |= ecx + ((u64)edx << 32);
 
        if ((xfeatures_mask_uabi() & XFEATURE_MASK_FPSSE) != XFEATURE_MASK_FPSSE) {
                /*
@@ -783,7 +777,7 @@ void __init fpu__init_system_xstate(unsigned int legacy_size)
                 * booting without it.  This is too early to BUG().
                 */
                pr_err("x86/fpu: FP/SSE not present amongst the CPU's xstate features: 0x%llx.\n",
-                      xfeatures_mask_all);
+                      fpu_kernel_cfg.max_features);
                goto out_disable;
        }
 
@@ -792,14 +786,21 @@ void __init fpu__init_system_xstate(unsigned int legacy_size)
         */
        for (i = 0; i < ARRAY_SIZE(xsave_cpuid_features); i++) {
                if (!boot_cpu_has(xsave_cpuid_features[i]))
-                       xfeatures_mask_all &= ~BIT_ULL(i);
+                       fpu_kernel_cfg.max_features &= ~BIT_ULL(i);
        }
 
-       xfeatures_mask_all &= XFEATURE_MASK_USER_SUPPORTED |
+       fpu_kernel_cfg.max_features &= XFEATURE_MASK_USER_SUPPORTED |
                              XFEATURE_MASK_SUPERVISOR_SUPPORTED;
 
+       fpu_user_cfg.max_features = fpu_kernel_cfg.max_features;
+       fpu_user_cfg.max_features &= XFEATURE_MASK_USER_SUPPORTED;
+
+       /* Identical for now */
+       fpu_kernel_cfg.default_features = fpu_kernel_cfg.max_features;
+       fpu_user_cfg.default_features = fpu_user_cfg.max_features;
+
        /* Store it for paranoia check at the end */
-       xfeatures = xfeatures_mask_all;
+       xfeatures = fpu_kernel_cfg.max_features;
 
        /* Enable xstate instructions to be able to continue with initialization: */
        fpu__init_cpu_xstate();
@@ -825,15 +826,15 @@ void __init fpu__init_system_xstate(unsigned int legacy_size)
         * Paranoia check whether something in the setup modified the
         * xfeatures mask.
         */
-       if (xfeatures != xfeatures_mask_all) {
+       if (xfeatures != fpu_kernel_cfg.max_features) {
                pr_err("x86/fpu: xfeatures modified from 0x%016llx to 0x%016llx during init, disabling XSAVE\n",
-                      xfeatures, xfeatures_mask_all);
+                      xfeatures, fpu_kernel_cfg.max_features);
                goto out_disable;
        }
 
        print_xstate_offset_size();
        pr_info("x86/fpu: Enabled xstate features 0x%llx, context size is %d bytes, using '%s' format.\n",
-               xfeatures_mask_all,
+               fpu_kernel_cfg.max_features,
                fpu_kernel_cfg.max_size,
                boot_cpu_has(X86_FEATURE_XSAVES) ? "compacted" : "standard");
        return;
@@ -908,7 +909,7 @@ void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr)
         * We should not ever be requesting features that we
         * have not enabled.
         */
-       WARN_ONCE(!(xfeatures_mask_all & BIT_ULL(xfeature_nr)),
+       WARN_ONCE(!(fpu_kernel_cfg.max_features & BIT_ULL(xfeature_nr)),
                  "get of unsupported state");
        /*
         * This assumes the last 'xsave*' instruction to