diff mbox

[2/3] KVM: PPC: Book3S: Move 64-bit KVM interrupt handler out from alt section

Message ID 20161221182927.24562-3-npiggin@gmail.com
State Accepted
Headers show

Commit Message

Nicholas Piggin Dec. 21, 2016, 6:29 p.m. UTC
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@gmail.com>
---
 arch/powerpc/include/asm/head-64.h   | 2 +-
 arch/powerpc/kernel/exceptions-64s.S | 6 ++----
 2 files changed, 3 insertions(+), 5 deletions(-)

Comments

Paul Mackerras Jan. 27, 2017, 2:25 a.m. UTC | #1
On Thu, Dec 22, 2016 at 04:29:26AM +1000, Nicholas Piggin wrote:
> 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@gmail.com>

Acked-by: Paul Mackerras <paulus@ozlabs.org>
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diff mbox

Patch

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 d39d6118c6e9..89b4f122aec6 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)