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);
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();
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;
*/
#include <asm/ppc_asm.h>
+#include <asm/code-patching-asm.h>
#include <asm/kvm_asm.h>
#include <asm/reg.h>
#include <asm/mmu.h>
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
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