From 7871fe2924c14e7109605cd4118dbc51f977f705 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 13 Oct 2021 16:55:31 +0200 Subject: [PATCH] x86/fpu: Replace KVMs xstate component clearing mainline inclusion from mainline-v5.16-rc1 commit 087df48c298c1cb829f4cd468d90f93234b1bc44 category: feature bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I590ZC CVE: NA Intel-SIG: commit 087df48c298c x86/fpu: Replace KVMs xstate component clearing. -------------------------------- In order to prepare for the support of dynamically enabled FPU features, move the clearing of xstate components to the FPU core code. No functional change. Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov Cc: kvm@vger.kernel.org Link: https://lkml.kernel.org/r/20211013145322.399567049@linutronix.de Signed-off-by: Lin Wang --- arch/x86/include/asm/fpu/api.h | 1 + arch/x86/include/asm/fpu/xstate.h | 1 - arch/x86/kernel/fpu/xstate.c | 12 +++++++++++- arch/x86/kernel/fpu/xstate.h | 2 ++ arch/x86/kvm/x86.c | 14 +++++--------- 5 files changed, 19 insertions(+), 11 deletions(-) diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h index 360cef8367a7..e78b03c477fd 100644 --- a/arch/x86/include/asm/fpu/api.h +++ b/arch/x86/include/asm/fpu/api.h @@ -105,6 +105,7 @@ DECLARE_PER_CPU(struct fpu *, fpu_fpregs_owner_ctx); /* fpstate-related functions which are exported to KVM */ extern void fpu_init_fpstate_user(struct fpu *fpu); +extern void fpstate_clear_xstate_component(struct fpstate *fps, unsigned int xfeature); /* KVM specific functions */ extern void fpu_swap_kvm_fpu(struct fpu *save, struct fpu *rstor, u64 restore_mask); diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h index b8cebc0ee420..fb329bbfe89f 100644 --- a/arch/x86/include/asm/fpu/xstate.h +++ b/arch/x86/include/asm/fpu/xstate.h @@ -128,7 +128,6 @@ extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS]; extern void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask); -void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr); int xfeature_size(int xfeature_nr); int copy_uabi_from_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf); int copy_sigframe_from_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf); diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index a096ca8aa741..99d967c605c0 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -908,7 +908,6 @@ void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr) return __raw_xsave_addr(xsave, xfeature_nr); } -EXPORT_SYMBOL_GPL(get_xsave_addr); #ifdef CONFIG_ARCH_HAS_PKEYS @@ -1257,6 +1256,17 @@ void xrstors(struct xregs_state *xstate, u64 mask) WARN_ON_ONCE(err); } +#if IS_ENABLED(CONFIG_KVM) +void fpstate_clear_xstate_component(struct fpstate *fps, unsigned int xfeature) +{ + void *addr = get_xsave_addr(&fps->regs.xsave, xfeature); + + if (addr) + memset(addr, 0, xstate_sizes[xfeature]); +} +EXPORT_SYMBOL_GPL(fpstate_clear_xstate_component); +#endif + #ifdef CONFIG_PROC_PID_ARCH_STATUS /* * Report the amount of time elapsed in millisecond since last AVX512 diff --git a/arch/x86/kernel/fpu/xstate.h b/arch/x86/kernel/fpu/xstate.h index bb6d7d298d2a..99f8cfec719d 100644 --- a/arch/x86/kernel/fpu/xstate.h +++ b/arch/x86/kernel/fpu/xstate.h @@ -21,6 +21,8 @@ extern void __copy_xstate_to_uabi_buf(struct membuf to, struct xregs_state *xsav extern void fpu__init_cpu_xstate(void); extern void fpu__init_system_xstate(void); +extern void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr); + /* XSAVE/XRSTOR wrapper functions */ #ifdef CONFIG_X86_64 diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 536ca4ceb504..8bdada03b9d7 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -10144,7 +10144,7 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) vcpu->arch.apf.halted = false; if (kvm_mpx_supported()) { - void *mpx_state_buffer; + struct fpstate *fpstate = vcpu->arch.guest_fpu->fpstate; /* * To avoid have the INIT path from kvm_apic_has_events() that be @@ -10152,14 +10152,10 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) */ if (init_event) kvm_put_guest_fpu(vcpu); - mpx_state_buffer = get_xsave_addr(&vcpu->arch.guest_fpu->state.xsave, - XFEATURE_BNDREGS); - if (mpx_state_buffer) - memset(mpx_state_buffer, 0, sizeof(struct mpx_bndreg_state)); - mpx_state_buffer = get_xsave_addr(&vcpu->arch.guest_fpu->state.xsave, - XFEATURE_BNDCSR); - if (mpx_state_buffer) - memset(mpx_state_buffer, 0, sizeof(struct mpx_bndcsr)); + + fpstate_clear_xstate_component(fpstate, XFEATURE_BNDREGS); + fpstate_clear_xstate_component(fpstate, XFEATURE_BNDCSR); + if (init_event) kvm_load_guest_fpu(vcpu); } -- GitLab