On Tue, Nov 19, 2024 at 04:35:00PM +0100, Valentin Schneider wrote:
@@ -418,9 +419,20 @@ static inline void cpu_tlbstate_update_lam(unsigned long lam, u64 untag_mask) #endif #endif /* !MODULE */ +#define __NATIVE_TLB_FLUSH_GLOBAL(suffix, cr4) \
- native_write_cr4##suffix(cr4 ^ X86_CR4_PGE); \
- native_write_cr4##suffix(cr4)
+#define NATIVE_TLB_FLUSH_GLOBAL(cr4) __NATIVE_TLB_FLUSH_GLOBAL(, cr4) +#define NATIVE_TLB_FLUSH_GLOBAL_NOINSTR(cr4) __NATIVE_TLB_FLUSH_GLOBAL(_noinstr, cr4)
static inline void __native_tlb_flush_global(unsigned long cr4) {
- native_write_cr4(cr4 ^ X86_CR4_PGE);
- native_write_cr4(cr4);
- NATIVE_TLB_FLUSH_GLOBAL(cr4);
}
+static inline void __native_tlb_flush_global_noinstr(unsigned long cr4) +{
- NATIVE_TLB_FLUSH_GLOBAL_NOINSTR(cr4);
+}
How about something like this instead? I've only compile tested the tlb.c bit, but it should get __flush_tlb_global() to be noinstr I think, including the Xen bit (unless I missed something but then objtool should complain).
--- diff --git a/arch/x86/include/asm/invpcid.h b/arch/x86/include/asm/invpcid.h index 734482afbf81..ff26136fcd9c 100644 --- a/arch/x86/include/asm/invpcid.h +++ b/arch/x86/include/asm/invpcid.h @@ -2,7 +2,7 @@ #ifndef _ASM_X86_INVPCID #define _ASM_X86_INVPCID
-static inline void __invpcid(unsigned long pcid, unsigned long addr, +static __always_inline void __invpcid(unsigned long pcid, unsigned long addr, unsigned long type) { struct { u64 d[2]; } desc = { { pcid, addr } }; @@ -13,7 +13,7 @@ static inline void __invpcid(unsigned long pcid, unsigned long addr, * mappings, we don't want the compiler to reorder any subsequent * memory accesses before the TLB flush. */ - asm volatile("invpcid %[desc], %[type]" + asm_inline volatile("invpcid %[desc], %[type]" :: [desc] "m" (desc), [type] "r" (type) : "memory"); }
@@ -23,26 +23,25 @@ static inline void __invpcid(unsigned long pcid, unsigned long addr, #define INVPCID_TYPE_ALL_NON_GLOBAL 3
/* Flush all mappings for a given pcid and addr, not including globals. */ -static inline void invpcid_flush_one(unsigned long pcid, - unsigned long addr) +static __always_inline void invpcid_flush_one(unsigned long pcid, unsigned long addr) { __invpcid(pcid, addr, INVPCID_TYPE_INDIV_ADDR); }
/* Flush all mappings for a given PCID, not including globals. */ -static inline void invpcid_flush_single_context(unsigned long pcid) +static __always_inline void invpcid_flush_single_context(unsigned long pcid) { __invpcid(pcid, 0, INVPCID_TYPE_SINGLE_CTXT); }
/* Flush all mappings, including globals, for all PCIDs. */ -static inline void invpcid_flush_all(void) +static __always_inline void invpcid_flush_all(void) { __invpcid(0, 0, INVPCID_TYPE_ALL_INCL_GLOBAL); }
/* Flush all mappings for all PCIDs except globals. */ -static inline void invpcid_flush_all_nonglobals(void) +static __always_inline void invpcid_flush_all_nonglobals(void) { __invpcid(0, 0, INVPCID_TYPE_ALL_NON_GLOBAL); } diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index d4eb9e1d61b8..b3daee3d4667 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -75,7 +75,7 @@ static inline void __flush_tlb_local(void) PVOP_VCALL0(mmu.flush_tlb_user); }
-static inline void __flush_tlb_global(void) +static __always_inline void __flush_tlb_global(void) { PVOP_VCALL0(mmu.flush_tlb_kernel); } diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h index a2dd24947eb8..b4c635b20538 100644 --- a/arch/x86/include/asm/xen/hypercall.h +++ b/arch/x86/include/asm/xen/hypercall.h @@ -357,8 +357,8 @@ MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req, trace_xen_mc_entry(mcl, 4); }
-static inline void -MULTI_mmuext_op(struct multicall_entry *mcl, struct mmuext_op *op, int count, +static __always_inline void +__MULTI_mmuext_op(struct multicall_entry *mcl, struct mmuext_op *op, int count, int *success_count, domid_t domid) { mcl->op = __HYPERVISOR_mmuext_op; @@ -366,6 +366,13 @@ MULTI_mmuext_op(struct multicall_entry *mcl, struct mmuext_op *op, int count, mcl->args[1] = count; mcl->args[2] = (unsigned long)success_count; mcl->args[3] = domid; +} + +static inline void +MULTI_mmuext_op(struct multicall_entry *mcl, struct mmuext_op *op, int count, + int *success_count, domid_t domid) +{ + __MULTI_mmuext_op(mcl, op, count, success_count, domid);
trace_xen_mc_entry(mcl, 4); } diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index b0d5a644fc84..0cfc00a34b7e 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -1168,9 +1168,10 @@ void flush_tlb_one_user(unsigned long addr) /* * Flush everything */ -STATIC_NOPV void native_flush_tlb_global(void) +STATIC_NOPV noinstr void native_flush_tlb_global(void) { unsigned long flags; + unsigned long cr4;
if (static_cpu_has(X86_FEATURE_INVPCID)) { /* @@ -1189,9 +1190,15 @@ STATIC_NOPV void native_flush_tlb_global(void) * be called from deep inside debugging code.) */ raw_local_irq_save(flags); - - __native_tlb_flush_global(this_cpu_read(cpu_tlbstate.cr4)); - + cr4 = this_cpu_read(cpu_tlbstate.cr4); + asm volatile("mov %0,%%cr4": : "r" (cr4 ^ X86_CR4_PGE) : "memory"); + asm volatile("mov %0,%%cr4": : "r" (cr4) : "memory"); + /* + * In lieu of not having the pinning crap, hard fail if CR4 doesn't + * match the expected value. This ensures that anybody doing dodgy gets + * the fallthrough check. + */ + BUG_ON(cr4 != this_cpu_read(cpu_tlbstate.cr4)); raw_local_irq_restore(flags); }
diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c index 55a4996d0c04..4eb265eb867a 100644 --- a/arch/x86/xen/mmu_pv.c +++ b/arch/x86/xen/mmu_pv.c @@ -1231,22 +1231,22 @@ static noinstr void xen_write_cr2(unsigned long cr2) this_cpu_read(xen_vcpu)->arch.cr2 = cr2; }
-static noinline void xen_flush_tlb(void) +static noinline noinstr void xen_flush_tlb(void) { struct mmuext_op *op; struct multicall_space mcs;
- preempt_disable(); + preempt_disable_notrace();
mcs = xen_mc_entry(sizeof(*op));
op = mcs.args; op->cmd = MMUEXT_TLB_FLUSH_LOCAL; - MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF); + __MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
- xen_mc_issue(XEN_LAZY_MMU); + __xen_mc_issue(XEN_LAZY_MMU);
- preempt_enable(); + preempt_enable_notrace(); }
static void xen_flush_tlb_one_user(unsigned long addr) diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h index e1b782e823e6..31eddca45c27 100644 --- a/arch/x86/xen/xen-ops.h +++ b/arch/x86/xen/xen-ops.h @@ -235,15 +235,19 @@ static inline struct multicall_space xen_mc_entry(size_t args) void xen_mc_flush(void);
/* Issue a multicall if we're not in a lazy mode */ -static inline void xen_mc_issue(unsigned mode) +static __always_inline void __xen_mc_issue(unsigned mode) { - trace_xen_mc_issue(mode); - if ((xen_get_lazy_mode() & mode) == 0) xen_mc_flush();
/* restore flags saved in xen_mc_batch */ - local_irq_restore(this_cpu_read(xen_mc_irq_flags)); + raw_local_irq_restore(this_cpu_read(xen_mc_irq_flags)); +} + +static inline void xen_mc_issue(unsigned mode) +{ + trace_xen_mc_issue(mode); + __xen_mc_issue(mode); }
/* Set up a callback to be called when the current batch is flushed */