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 | 27 |
3 files changed, 38 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h index fb5f911b0d91..2d4444981c2c 100644 --- a/arch/powerpc/include/asm/asm-prototypes.h +++ b/arch/powerpc/include/asm/asm-prototypes.h @@ -130,7 +130,9 @@ unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip); 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 88e582d2bad7..f5d6541bf8c2 100644 --- a/arch/powerpc/kernel/security.c +++ b/arch/powerpc/kernel/security.c @@ -392,6 +392,9 @@ 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(); @@ -402,6 +405,12 @@ 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 663a398449b7..46ea42f40334 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> @@ -1445,6 +1446,10 @@ mc_cont: 1: #endif /* CONFIG_KVM_XICS */ + /* Possibly flush the link stack here. */ +1: nop + patch_site 1b patch__call_kvm_flush_link_stack + stw r12, STACK_SLOT_TRAP(r1) mr r3, r12 /* Increment exit count, poke other threads to exit */ @@ -1957,6 +1962,28 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX) 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 + /* * 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 |