diff options
| author | Chao Gao <chao.gao@intel.com> | 2025-05-22 08:10:07 -0700 |
|---|---|---|
| committer | Dave Hansen <dave.hansen@linux.intel.com> | 2025-06-24 13:46:32 -0700 |
| commit | fafb29e18db2eef75edafd4240fcde8b5da2c948 (patch) | |
| tree | 0ccf69fe32634db4827531cc39247cb1382edcd3 | |
| parent | 509e880b779592aafb41b3b23de3df7e4e2e2fcf (diff) | |
x86/fpu: Remove xfd argument from __fpstate_reset()
The initial values for fpstate::xfd differ between guest and host fpstates.
Currently, the initial values are passed as an argument to
__fpstate_reset(). But, __fpstate_reset() already assigns different default
features and sizes based on the type of fpstates (i.e., guest or host). So,
handle fpstate::xfd in a similar way to highlight the differences in the
initial xfd value between guest and host fpstates
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Chao Gao <chao.gao@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: John Allen <john.allen@amd.com>
Link: https://lore.kernel.org/all/aBuf7wiiDT0Wflhk@google.com/
Link: https://lore.kernel.org/all/20250522151031.426788-5-chao.gao%40intel.com
| -rw-r--r-- | arch/x86/kernel/fpu/core.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index e02705187bbf..aefd412a23dc 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -218,7 +218,7 @@ void fpu_reset_from_exception_fixup(void) } #if IS_ENABLED(CONFIG_KVM) -static void __fpstate_reset(struct fpstate *fpstate, u64 xfd); +static void __fpstate_reset(struct fpstate *fpstate); static void fpu_lock_guest_permissions(void) { @@ -253,8 +253,7 @@ bool fpu_alloc_guest_fpstate(struct fpu_guest *gfpu) fpstate->is_valloc = true; fpstate->is_guest = true; - /* Leave xfd to 0 (the reset value defined by spec) */ - __fpstate_reset(fpstate, 0); + __fpstate_reset(fpstate); fpstate_init_user(fpstate); gfpu->fpstate = fpstate; @@ -545,7 +544,7 @@ void fpstate_init_user(struct fpstate *fpstate) fpstate_init_fstate(fpstate); } -static void __fpstate_reset(struct fpstate *fpstate, u64 xfd) +static void __fpstate_reset(struct fpstate *fpstate) { /* * Supervisor features (and thus sizes) may diverge between guest @@ -553,25 +552,29 @@ static void __fpstate_reset(struct fpstate *fpstate, u64 xfd) * for guests despite not being utilized by the host. User * features and sizes are always identical, which allows for * common guest and userspace ABI. + * + * For the host, set XFD to the kernel's desired initialization + * value. For guests, set XFD to its architectural RESET value. */ if (fpstate->is_guest) { fpstate->size = guest_default_cfg.size; fpstate->xfeatures = guest_default_cfg.features; + fpstate->xfd = 0; } else { fpstate->size = fpu_kernel_cfg.default_size; fpstate->xfeatures = fpu_kernel_cfg.default_features; + fpstate->xfd = init_fpstate.xfd; } fpstate->user_size = fpu_user_cfg.default_size; fpstate->user_xfeatures = fpu_user_cfg.default_features; - fpstate->xfd = xfd; } void fpstate_reset(struct fpu *fpu) { /* Set the fpstate pointer to the default fpstate */ fpu->fpstate = &fpu->__fpstate; - __fpstate_reset(fpu->fpstate, init_fpstate.xfd); + __fpstate_reset(fpu->fpstate); /* Initialize the permission related info in fpu */ fpu->perm.__state_perm = fpu_kernel_cfg.default_features; |