[ZESTY] [PATCH 05/33] KVM: PPC: Book3S: Move 64-bit KVM interrupt handler out from alt section

[Breno Leitao]

From: Nicholas Piggin <npiggin at gmail.com>

BugLink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1675806

A subsequent patch to make KVM handlers relocation-safe makes them
unusable from within alt section "else" cases (due to the way fixed
addresses are taken from within fixed section head code).

Stop open-coding the KVM handlers, and add them both as normal. A more
optimal fix may be to allow some level of alternate feature patching in
the exception macros themselves, but for now this will do.

The TRAMP_KVM handlers must be moved to the "virt" fixed section area
(name is arbitrary) in order to be closer to .text and avoid the dreaded
"relocation truncated to fit" error.

Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
Acked-by: Paul Mackerras <paulus at ozlabs.org>
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
(cherry picked from commit 7ede531773ea69fa56b02a873ed83ce3507eb8d5)
Signed-off-by: Breno Leitao <breno.leitao at gmail.com>
---
 arch/powerpc/include/asm/head-64.h   | 2 +-
 arch/powerpc/kernel/exceptions-64s.S | 6 ++----
 2 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/head-64.h b/arch/powerpc/include/asm/head-64.h
index fca7033839a9..9bd81619d090 100644
--- a/arch/powerpc/include/asm/head-64.h
+++ b/arch/powerpc/include/asm/head-64.h
@@ -218,7 +218,7 @@ end_##sname:
 
 #ifdef CONFIG_KVM_BOOK3S_64_HANDLER
 #define TRAMP_KVM_BEGIN(name)						\
-	TRAMP_REAL_BEGIN(name)
+	TRAMP_VIRT_BEGIN(name)
 #else
 #define TRAMP_KVM_BEGIN(name)
 #endif
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 069aac8af909..37252f306529 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -717,13 +717,9 @@ hardware_interrupt_hv:
 	BEGIN_FTR_SECTION
 		_MASKABLE_EXCEPTION_PSERIES(0x500, hardware_interrupt_common,
 					    EXC_HV, SOFTEN_TEST_HV)
-do_kvm_H0x500:
-		KVM_HANDLER(PACA_EXGEN, EXC_HV, 0x502)
 	FTR_SECTION_ELSE
 		_MASKABLE_EXCEPTION_PSERIES(0x500, hardware_interrupt_common,
 					    EXC_STD, SOFTEN_TEST_PR)
-do_kvm_0x500:
-		KVM_HANDLER(PACA_EXGEN, EXC_STD, 0x500)
 	ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
 EXC_REAL_END(hardware_interrupt, 0x500, 0x600)
 
@@ -737,6 +733,8 @@ hardware_interrupt_relon_hv:
 	ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE)
 EXC_VIRT_END(hardware_interrupt, 0x4500, 0x4600)
 
+TRAMP_KVM(PACA_EXGEN, 0x500)
+TRAMP_KVM_HV(PACA_EXGEN, 0x500)
 EXC_COMMON_ASYNC(hardware_interrupt_common, 0x500, do_IRQ)
 
 
-- 
2.11.0