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 | 20 |
3 files changed, 31 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h index 7c74384c0146..77c6bfe60137 100644 --- a/arch/powerpc/include/asm/asm-prototypes.h +++ b/arch/powerpc/include/asm/asm-prototypes.h @@ -16,7 +16,9 @@ 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 long flush_count_cache; +extern long kvm_flush_link_stack; #endif /* _ASM_POWERPC_ASM_PROTOTYPES_H */ diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c index c6f8150c3b65..156cfe6d23b0 100644 --- a/arch/powerpc/kernel/security.c +++ b/arch/powerpc/kernel/security.c @@ -391,6 +391,9 @@ 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(); @@ -401,6 +404,12 @@ 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 4463718ae614..c8b9194567d6 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -18,6 +18,7 @@ */ #include <asm/ppc_asm.h> +#include <asm/code-patching-asm.h> #include <asm/kvm_asm.h> #include <asm/reg.h> #include <asm/mmu.h> @@ -1169,6 +1170,10 @@ mc_cont: bl kvmhv_accumulate_time #endif + /* Possibly flush the link stack here. */ +1: nop + patch_site 1b patch__call_kvm_flush_link_stack + mr r3, r12 /* Increment exit count, poke other threads to exit */ bl kvmhv_commence_exit @@ -1564,6 +1569,21 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) 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 + + /* Restore LR */ + mtlr r0 + blr + /* * Check whether an HDSI is an HPTE not found fault or something else. * If it is an HPTE not found fault that is due to the guest accessing |