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-rw-r--r--arch/powerpc/include/asm/exception-64s.h13
-rw-r--r--arch/powerpc/kernel/exceptions-64s.S42
-rw-r--r--arch/powerpc/kvm/book3s_64_entry.S30
3 files changed, 44 insertions, 41 deletions
diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index c1a8aac01cf9..bb6f78fcf981 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -35,6 +35,19 @@
/* PACA save area size in u64 units (exgen, exmc, etc) */
#define EX_SIZE 10
+/* PACA save area offsets */
+#define EX_R9 0
+#define EX_R10 8
+#define EX_R11 16
+#define EX_R12 24
+#define EX_R13 32
+#define EX_DAR 40
+#define EX_DSISR 48
+#define EX_CCR 52
+#define EX_CFAR 56
+#define EX_PPR 64
+#define EX_CTR 72
+
/*
* maximum recursive depth of MCE exceptions
*/
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 4819bf60324c..03e2d65d3d3f 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -21,22 +21,6 @@
#include <asm/feature-fixups.h>
#include <asm/kup.h>
-/* PACA save area offsets (exgen, exmc, etc) */
-#define EX_R9 0
-#define EX_R10 8
-#define EX_R11 16
-#define EX_R12 24
-#define EX_R13 32
-#define EX_DAR 40
-#define EX_DSISR 48
-#define EX_CCR 52
-#define EX_CFAR 56
-#define EX_PPR 64
-#define EX_CTR 72
-.if EX_SIZE != 10
- .error "EX_SIZE is wrong"
-.endif
-
/*
* Following are fixed section helper macros.
*
@@ -1941,29 +1925,8 @@ EXC_VIRT_END(system_call, 0x4c00, 0x100)
#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
TRAMP_REAL_BEGIN(system_call_kvm)
- /*
- * This is a hcall, so register convention is as above, with these
- * differences:
- * r13 = PACA
- * ctr = orig r13
- * orig r10 saved in PACA
- */
- /*
- * Save the PPR (on systems that support it) before changing to
- * HMT_MEDIUM. That allows the KVM code to save that value into the
- * guest state (it is the guest's PPR value).
- */
-BEGIN_FTR_SECTION
- mfspr r10,SPRN_PPR
- std r10,HSTATE_PPR(r13)
-END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
- HMT_MEDIUM
mfctr r10
- SET_SCRATCH0(r10)
- mfcr r10
- std r12,HSTATE_SCRATCH0(r13)
- sldi r12,r10,32
- ori r12,r12,0xc00
+ SET_SCRATCH0(r10) /* Save r13 in SCRATCH0 */
#ifdef CONFIG_RELOCATABLE
/*
* Requires __LOAD_FAR_HANDLER beause kvmppc_hcall lives
@@ -1971,15 +1934,12 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
*/
__LOAD_FAR_HANDLER(r10, kvmppc_hcall)
mtctr r10
- ld r10,PACA_EXGEN+EX_R10(r13)
bctr
#else
- ld r10,PACA_EXGEN+EX_R10(r13)
b kvmppc_hcall
#endif
#endif
-
/**
* Interrupt 0xd00 - Trace Interrupt.
* This is a synchronous interrupt in response to instruction step or
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index c21fa64059ef..f527e16707db 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -14,6 +14,36 @@
.global kvmppc_hcall
.balign IFETCH_ALIGN_BYTES
kvmppc_hcall:
+ /*
+ * This is a hcall, so register convention is as
+ * Documentation/powerpc/papr_hcalls.rst, with these additions:
+ * R13 = PACA
+ * guest R13 saved in SPRN_SCRATCH0
+ * R10 = free
+ * guest r10 saved in PACA_EXGEN
+ *
+ * This may also be a syscall from PR-KVM userspace that is to be
+ * reflected to the PR guest kernel, so registers may be set up for
+ * a system call rather than hcall. We don't currently clobber
+ * anything here, but the 0xc00 handler has already clobbered CTR
+ * and CR0, so PR-KVM can not support a guest kernel that preserves
+ * those registers across its system calls.
+ */
+ /*
+ * Save the PPR (on systems that support it) before changing to
+ * HMT_MEDIUM. That allows the KVM code to save that value into the
+ * guest state (it is the guest's PPR value).
+ */
+BEGIN_FTR_SECTION
+ mfspr r10,SPRN_PPR
+ std r10,HSTATE_PPR(r13)
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+ HMT_MEDIUM
+ mfcr r10
+ std r12,HSTATE_SCRATCH0(r13)
+ sldi r12,r10,32
+ ori r12,r12,0xc00
+ ld r10,PACA_EXGEN+EX_R10(r13)
.global kvmppc_interrupt
.balign IFETCH_ALIGN_BYTES