From: Wei Chen <Wei.Chen@arm.com>
To: xen-devel@lists.xen.org
Cc: sstabellini@kernel.org, wei.chen@arm.com, steve.capper@arm.com,
Kaly.Xin@arm.com, julien.grall@arm.com, nd@arm.com
Subject: [PATCH v4 10/19] xen/arm32: Use alternative to skip the check of pending serrors
Date: Wed, 5 Apr 2017 17:09:12 +0800 [thread overview]
Message-ID: <1491383361-22886-11-git-send-email-Wei.Chen@arm.com> (raw)
In-Reply-To: <1491383361-22886-1-git-send-email-Wei.Chen@arm.com>
We have provided an option to administrator to determine how to
handle the SErrors. In order to skip the check of pending SError,
in conventional way, we have to read the option every time before
we try to check the pending SError. This will add overhead to check
the option at every trap.
The ARM32 supports the alternative patching feature. We can use an
ALTERNATIVE to avoid checking option at every trap. We added a new
cpufeature named "SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT". This feature
will be enabled when the option is not diverse.
Signed-off-by: Wei Chen <Wei.Chen@arm.com>
Reviewed-by: Julien Grall <julien.grall@arm.com>
---
xen/arch/arm/arm32/entry.S | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/xen/arch/arm/arm32/entry.S b/xen/arch/arm/arm32/entry.S
index 2187226..8cd2123 100644
--- a/xen/arch/arm/arm32/entry.S
+++ b/xen/arch/arm/arm32/entry.S
@@ -1,5 +1,6 @@
#include <asm/asm_defns.h>
#include <asm/regs.h>
+#include <asm/alternative.h>
#include <public/xen.h>
#define SAVE_ONE_BANKED(reg) mrs r11, reg; str r11, [sp, #UREGS_##reg]
@@ -44,6 +45,14 @@ save_guest_regs:
SAVE_BANKED(fiq)
SAVE_ONE_BANKED(R8_fiq); SAVE_ONE_BANKED(R9_fiq); SAVE_ONE_BANKED(R10_fiq)
SAVE_ONE_BANKED(R11_fiq); SAVE_ONE_BANKED(R12_fiq);
+
+ /*
+ * If the SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT has been set in the cpu
+ * feature, the checking of pending SErrors will be skipped.
+ */
+ ALTERNATIVE("nop",
+ "b skip_check",
+ SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT)
/*
* Start to check pending virtual abort in the gap of Guest -> HYP
* world switch.
@@ -99,6 +108,7 @@ abort_guest_exit_end:
*/
bne return_from_trap
+skip_check:
mov pc, lr
#define DEFINE_TRAP_ENTRY(trap) \
--
2.7.4
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next prev parent reply other threads:[~2017-04-05 9:09 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-05 9:09 [PATCH v4 00/19] Provide a command line option to choose how to handle SErrors Wei Chen
2017-04-05 9:09 ` [PATCH v4 01/19] xen/arm: Save ESR_EL2 to avoid using mismatched value in syndrome check Wei Chen
2017-04-05 9:09 ` [PATCH v4 02/19] xen/arm: Introduce a helper to get default HCR_EL2 flags Wei Chen
2017-04-05 9:09 ` [PATCH v4 03/19] xen/arm: Set and restore HCR_EL2 register for each vCPU separately Wei Chen
2017-04-05 9:09 ` [PATCH v4 04/19] xen/arm: Avoid setting/clearing HCR_RW at every context switch Wei Chen
2017-04-05 9:09 ` [PATCH v4 05/19] xen/arm: Save HCR_EL2 when a guest took the SError Wei Chen
2017-04-05 9:09 ` [PATCH v4 06/19] xen/arm: Introduce a virtual abort injection helper Wei Chen
2017-04-05 9:09 ` [PATCH v4 07/19] xen/arm: Introduce a command line parameter for SErrors/Aborts Wei Chen
2017-04-05 9:09 ` [PATCH v4 08/19] xen/arm: Introduce a initcall to update cpu_hwcaps by serror_op Wei Chen
2017-04-05 9:09 ` [PATCH v4 09/19] xen/arm64: Use alternative to skip the check of pending serrors Wei Chen
2017-04-05 9:09 ` Wei Chen [this message]
2017-04-05 9:09 ` [PATCH v4 11/19] xen/arm: Move macro VABORT_GEN_BY_GUEST to common header Wei Chen
2017-04-05 9:09 ` [PATCH v4 12/19] xen/arm: Introduce new helpers to handle guest/hyp SErrors Wei Chen
2017-04-05 9:09 ` [PATCH v4 13/19] xen/arm: Replace do_trap_guest_serror with new helpers Wei Chen
2017-04-05 9:09 ` [PATCH v4 14/19] xen/arm: Unmask the Abort/SError bit in the exception entries Wei Chen
2017-04-05 9:09 ` [PATCH v4 15/19] xen/arm: Introduce a helper to check local abort is enabled Wei Chen
2017-04-05 11:14 ` Julien Grall
2017-04-05 9:09 ` [PATCH v4 16/19] xen/arm: Introduce a macro to synchronize SError Wei Chen
2017-04-05 11:15 ` Julien Grall
2017-04-05 9:09 ` [PATCH v4 17/19] xen/arm: Isolate the SError between the context switch of 2 vCPUs Wei Chen
2017-04-05 9:09 ` [PATCH v4 18/19] xen/arm: Prevent slipping hypervisor SError to guest Wei Chen
2017-04-05 11:17 ` Julien Grall
2017-04-05 9:09 ` [PATCH v4 19/19] xen/arm: Handle guest external abort as guest SError Wei Chen
2017-04-05 19:18 ` [PATCH v4 00/19] Provide a command line option to choose how to handle SErrors Stefano Stabellini
2017-04-06 4:52 ` Wei Chen
2017-04-07 15:37 ` Julien Grall
2017-04-07 23:20 ` Stefano Stabellini
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