[PATCH 17/27] Make head_64.S aware of KVM real mode code

Alexander Graf
2009-10-21T15:03:23Z

We need to run some KVM trampoline code in real mode. Unfortunately, real mode
only covers 8MB on Cell so we need to squeeze ourselves as low as possible.

Also, we need to trap interrupts to get us back from guest state to host state
without telling Linux about it.

This patch adds interrupt traps and includes the KVM code that requires real
mode in the real mode parts of Linux.

Signed-off-by: Alexander Graf <agraf-l3A5Bk7waGM@public.gmane.org>
---
arch/powerpc/include/asm/exception-64s.h | 2 ++
arch/powerpc/kernel/exceptions-64s.S | 8 ++++++++
arch/powerpc/kernel/head_64.S | 7 +++++++
3 files changed, 17 insertions(+), 0 deletions(-)

diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index a98653b..57c4000 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -147,6 +147,7 @@
.globl label##_pSeries; \
label##_pSeries: \
HMT_MEDIUM; \
+ DO_KVM n; \
mtspr SPRN_SPRG_SCRATCH0,r13; /* save r13 */ \
EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common)

@@ -170,6 +171,7 @@ label##_pSeries: \
.globl label##_pSeries; \
label##_pSeries: \
HMT_MEDIUM; \
+ DO_KVM n; \
mtspr SPRN_SPRG_SCRATCH0,r13; /* save r13 */ \
mfspr r13,SPRN_SPRG_PACA; /* get paca address into r13 */ \
std r9,PACA_EXGEN+EX_R9(r13); /* save r9, r10 */ \
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 1808876..fc3ead0 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -41,6 +41,7 @@ __start_interrupts:
. = 0x200
_machine_check_pSeries:
HMT_MEDIUM
+ DO_KVM 0x200
mtspr SPRN_SPRG_SCRATCH0,r13 /* save r13 */
EXCEPTION_PROLOG_PSERIES(PACA_EXMC, machine_check_common)

@@ -48,6 +49,7 @@ _machine_check_pSeries:
.globl data_access_pSeries
data_access_pSeries:
HMT_MEDIUM
+ DO_KVM 0x300
mtspr SPRN_SPRG_SCRATCH0,r13
BEGIN_FTR_SECTION
mfspr r13,SPRN_SPRG_PACA
@@ -77,6 +79,7 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_SLB)
.globl data_access_slb_pSeries
data_access_slb_pSeries:
HMT_MEDIUM
+ DO_KVM 0x380
mtspr SPRN_SPRG_SCRATCH0,r13
mfspr r13,SPRN_SPRG_PACA /* get paca address into r13 */
std r3,PACA_EXSLB+EX_R3(r13)
@@ -115,6 +118,7 @@ data_access_slb_pSeries:
.globl instruction_access_slb_pSeries
instruction_access_slb_pSeries:
HMT_MEDIUM
+ DO_KVM 0x480
mtspr SPRN_SPRG_SCRATCH0,r13
mfspr r13,SPRN_SPRG_PACA /* get paca address into r13 */
std r3,PACA_EXSLB+EX_R3(r13)
@@ -154,6 +158,7 @@ instruction_access_slb_pSeries:
.globl system_call_pSeries
system_call_pSeries:
HMT_MEDIUM
+ DO_KVM 0xc00
BEGIN_FTR_SECTION
cmpdi r0,0x1ebe
beq- 1f
@@ -186,12 +191,15 @@ END_FTR_SECTION_IFSET(CPU_FTR_REAL_LE)
* trickery is thus necessary
*/
. = 0xf00
+ DO_KVM 0xf00
b performance_monitor_pSeries

. = 0xf20
+ DO_KVM 0xf20
b altivec_unavailable_pSeries

. = 0xf40
+ DO_KVM 0xf40
b vsx_unavailable_pSeries

#ifdef CONFIG_CBE_RAS
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index c38afdb..9258074 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -37,6 +37,7 @@
#include <asm/firmware.h>
#include <asm/page_64.h>
#include <asm/irqflags.h>
+#include <asm/kvm_book3s_64_asm.h>

/* The physical memory is layed out such that the secondary processor
* spin code sits at 0x0000...0x00ff. On server, the vectors follow
@@ -165,6 +166,12 @@ exception_marker:
#include "exceptions-64s.S"
#endif

+/* KVM trampoline code needs to be close to the interrupt handlers */
+
+#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
+#include "../kvm/book3s_64_rmhandlers.S"
+#endif
+
_GLOBAL(generic_secondary_thread_init)
mr r24,r3

--
1.6.0.2