From: Marc Zyngier <marc.zyngier@arm.com>
To: "Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>
Cc: Andre Przywara <andre.przywara@arm.com>,
Andrew Murray <andrew.murray@arm.com>,
Dave Martin <Dave.Martin@arm.com>,
Eric Auger <eric.auger@redhat.com>,
James Morse <james.morse@arm.com>,
Julien Thierry <julien.thierry@arm.com>,
Steven Price <steven.price@arm.com>,
Sudeep Holla <sudeep.holla@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH 01/18] arm64: assembler: Switch ESB-instruction with a vanilla nop if !ARM64_HAS_RAS
Date: Tue, 9 Jul 2019 13:24:50 +0100 [thread overview]
Message-ID: <20190709122507.214494-2-marc.zyngier@arm.com> (raw)
In-Reply-To: <20190709122507.214494-1-marc.zyngier@arm.com>
From: James Morse <james.morse@arm.com>
The ESB-instruction is a nop on CPUs that don't implement the RAS
extensions. This lets us use it in places like the vectors without
having to use alternatives.
If someone disables CONFIG_ARM64_RAS_EXTN, this instruction still has
its RAS extensions behaviour, but we no longer read DISR_EL1 as this
register does depend on alternatives.
This could go wrong if we want to synchronize an SError from a KVM
guest. On a CPU that has the RAS extensions, but the KConfig option
was disabled, we consume the pending SError with no chance of ever
reading it.
Hide the ESB-instruction behind the CONFIG_ARM64_RAS_EXTN option,
outputting a regular nop if the feature has been disabled.
Reported-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
arch/arm64/include/asm/assembler.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index 570d195a184d..e3a15c751b13 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -96,7 +96,11 @@
* RAS Error Synchronization barrier
*/
.macro esb
+#ifdef CONFIG_ARM64_RAS_EXTN
hint #16
+#else
+ nop
+#endif
.endm
/*
--
2.20.1
next prev parent reply other threads:[~2019-07-09 12:25 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-09 12:24 [GIT PULL] KVM/arm updates for Linux 5.3 Marc Zyngier
2019-07-09 12:24 ` Marc Zyngier [this message]
2019-07-09 12:24 ` [PATCH 02/18] KVM: arm64: Abstract the size of the HYP vectors pre-amble Marc Zyngier
2019-07-09 12:24 ` [PATCH 03/18] KVM: arm64: Make indirect vectors preamble behaviour symmetric Marc Zyngier
2019-07-09 12:24 ` [PATCH 04/18] KVM: arm64: Consume pending SError as early as possible Marc Zyngier
2019-07-09 12:24 ` [PATCH 05/18] KVM: arm64: Defer guest entry when an asynchronous exception is pending Marc Zyngier
2019-07-09 12:24 ` [PATCH 06/18] arm64: Update silicon-errata.txt for Neoverse-N1 #1349291 Marc Zyngier
2019-07-09 12:24 ` [PATCH 07/18] KVM: arm64: Re-mask SError after the one instruction window Marc Zyngier
2019-07-09 12:24 ` [PATCH 08/18] KVM: arm64: Skip more of the SError vaxorcism Marc Zyngier
2019-07-09 12:24 ` [PATCH 09/18] KVM: arm/arm64: Rename kvm_pmu_{enable/disable}_counter functions Marc Zyngier
2019-07-09 12:24 ` [PATCH 10/18] KVM: arm/arm64: Extract duplicated code to own function Marc Zyngier
2019-07-09 12:25 ` [PATCH 11/18] KVM: arm/arm64: Re-create event when setting counter value Marc Zyngier
2019-07-09 12:25 ` [PATCH 12/18] KVM: arm/arm64: Remove pmc->bitmask Marc Zyngier
2019-07-09 12:25 ` [PATCH 13/18] KVM: arm/arm64: Support chained PMU counters Marc Zyngier
2019-07-09 12:25 ` [PATCH 14/18] arm64: KVM: Propagate full Spectre v2 workaround state to KVM guests Marc Zyngier
2019-07-09 12:25 ` [PATCH 15/18] KVM: arm/arm64: Add save/restore support for firmware workaround state Marc Zyngier
2019-07-09 12:25 ` [PATCH 16/18] KVM: doc: Add API documentation on the KVM_REG_ARM_WORKAROUNDS register Marc Zyngier
2019-07-09 12:25 ` [PATCH 17/18] KVM: arm64: Migrate _elx sysreg accessors to msr_s/mrs_s Marc Zyngier
2019-07-09 12:25 ` [PATCH 18/18] KVM: arm/arm64: Initialise host's MPIDRs by reading the actual register Marc Zyngier
2019-07-11 13:40 ` [GIT PULL] KVM/arm updates for Linux 5.3 Paolo Bonzini
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