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-rw-r--r--arch/powerpc/kvm/book3s_hv_rmhandlers.S27
1 files changed, 27 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 79a180cf4c94..4b60bec20603 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>
@@ -1266,6 +1267,10 @@ mc_cont:
bl kvmhv_accumulate_time
#endif
+ /* Possibly flush the link stack here. */
+1: nop
+ patch_site 1b patch__call_kvm_flush_link_stack
+
stw r12, STACK_SLOT_TRAP(r1)
mr r3, r12
/* Increment exit count, poke other threads to exit */
@@ -1685,6 +1690,28 @@ 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
+
+ /* 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