diff options
| -rw-r--r-- | arch/powerpc/include/asm/asm-prototypes.h | 2 | ||||
| -rw-r--r-- | arch/powerpc/kernel/security.c | 9 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_rmhandlers.S | 30 |
3 files changed, 41 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h index 3ee92f692e64..d84d1417ddb6 100644 --- a/arch/powerpc/include/asm/asm-prototypes.h +++ b/arch/powerpc/include/asm/asm-prototypes.h @@ -153,9 +153,11 @@ void _kvmppc_save_tm_pr(struct kvm_vcpu *vcpu, u64 guest_msr); extern s32 patch__call_flush_count_cache; extern s32 patch__flush_count_cache_return; extern s32 patch__flush_link_stack_return; +extern s32 patch__call_kvm_flush_link_stack; extern s32 patch__memset_nocache, patch__memcpy_nocache; extern long flush_count_cache; +extern long kvm_flush_link_stack; #ifdef CONFIG_PPC_TRANSACTIONAL_MEM void kvmppc_save_tm_hv(struct kvm_vcpu *vcpu, u64 msr, bool preserve_nv); diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c index a3138e7d71bb..bd91dceb7010 100644 --- a/arch/powerpc/kernel/security.c +++ b/arch/powerpc/kernel/security.c @@ -400,6 +400,9 @@ static void toggle_count_cache_flush(bool enable) if (!enable) { patch_instruction_site(&patch__call_flush_count_cache, PPC_INST_NOP); +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + patch_instruction_site(&patch__call_kvm_flush_link_stack, PPC_INST_NOP); +#endif pr_info("link-stack-flush: software flush disabled.\n"); link_stack_flush_enabled = false; no_count_cache_flush(); @@ -410,6 +413,12 @@ static void toggle_count_cache_flush(bool enable) patch_branch_site(&patch__call_flush_count_cache, (u64)&flush_count_cache, BRANCH_SET_LINK); +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + // This enables the branch from guest_exit_cont to kvm_flush_link_stack + patch_branch_site(&patch__call_kvm_flush_link_stack, + (u64)&kvm_flush_link_stack, BRANCH_SET_LINK); +#endif + pr_info("link-stack-flush: software flush enabled.\n"); link_stack_flush_enabled = true; diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index faebcbb8c4db..0496e66aaa56 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -11,6 +11,7 @@ */ #include <asm/ppc_asm.h> +#include <asm/code-patching-asm.h> #include <asm/kvm_asm.h> #include <asm/reg.h> #include <asm/mmu.h> @@ -1487,6 +1488,13 @@ guest_exit_cont: /* r9 = vcpu, r12 = trap, r13 = paca */ 1: #endif /* CONFIG_KVM_XICS */ + /* + * Possibly flush the link stack here, before we do a blr in + * guest_exit_short_path. + */ +1: nop + patch_site 1b patch__call_kvm_flush_link_stack + /* If we came in through the P9 short path, go back out to C now */ lwz r0, STACK_SLOT_SHORT_PATH(r1) cmpwi r0, 0 @@ -1963,6 +1971,28 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300) mtlr r0 blr +.balign 32 +.global kvm_flush_link_stack +kvm_flush_link_stack: + /* Save LR into r0 */ + mflr r0 + + /* Flush the link stack. On Power8 it's up to 32 entries in size. */ + .rept 32 + bl .+4 + .endr + + /* And on Power9 it's up to 64. */ +BEGIN_FTR_SECTION + .rept 32 + bl .+4 + .endr +END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300) + + /* Restore LR */ + mtlr r0 + blr + kvmppc_guest_external: /* External interrupt, first check for host_ipi. If this is * set, we know the host wants us out so let's do it now |