This sets up the same calling convention from interrupt entry to
KVM interrupt handler for system calls as exists for other interrupt
types.
This is a better API, it uses a save area rather than SPR, and it has
more registers free to use. Using a single common API helps maintain
it, and it becomes easier to use in C in a later patch.
Reviewed-by: Alexey Kardashevskiy <a...@ozlabs.ru>
Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
arch/powerpc/kernel/exceptions-64s.S | 21 +++++++++++++++-
arch/powerpc/kvm/book3s_64_entry.S | 37 +++++++++-------------------
2 files changed, 32 insertions(+), 26 deletions(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S
b/arch/powerpc/kernel/exceptions-64s.S
index 115cf79f3e82..4615057681c3 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1892,8 +1892,27 @@ EXC_VIRT_END(system_call, 0x4c00, 0x100)
#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
TRAMP_REAL_BEGIN(kvm_hcall)
+ std r9,PACA_EXGEN+EX_R9(r13)
+ std r11,PACA_EXGEN+EX_R11(r13)
+ std r12,PACA_EXGEN+EX_R12(r13)
+ mfcr r9
mfctr r10
- SET_SCRATCH0(r10) /* Save r13 in SCRATCH0 */
+ std r10,PACA_EXGEN+EX_R13(r13)
+ li r10,0
+ std r10,PACA_EXGEN+EX_CFAR(r13)
+ std r10,PACA_EXGEN+EX_CTR(r13)
+ /*
+ * 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,PACA_EXGEN+EX_PPR(r13)
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+
+ HMT_MEDIUM
+
#ifdef CONFIG_RELOCATABLE
/*
* Requires __LOAD_FAR_HANDLER beause kvmppc_hcall lives
diff --git a/arch/powerpc/kvm/book3s_64_entry.S
b/arch/powerpc/kvm/book3s_64_entry.S
index b6149df21de3..de81ab69555b 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -11,33 +11,21 @@
* These are branched to from interrupt handlers in exception-64s.S which set
* IKVM_REAL or IKVM_VIRT, if HSTATE_IN_GUEST was found to be non-zero.
*/
+
+/*
+ * This is a hcall, so guest register call convention is as
+ * Documentation/powerpc/papr_hcalls.rst.
+ *
+ * The state of registers is as below, except CFAR is not saved, R13 is not
+ * in SCRATCH0, and R10 does not contain the trap.
+ */
.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
- */
- /*
- * 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)
- b do_kvm_interrupt
+ ld r10,PACA_EXGEN+EX_R13(r13)
+ SET_SCRATCH0(r10)
+ li r10,0xc00
+ /* Now we look like kvmppc_interrupt */
/*
* KVM interrupt entry occurs after GEN_INT_ENTRY runs, and follows that
@@ -84,7 +72,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
ld r10,EX_R10(r11)
ld r11,EX_R11(r11)
-do_kvm_interrupt:
/*
* Hcalls and other interrupts come here after normalising register
* contents and save locations:
--
2.23.0
