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From: Andrew Scull <ascull@google.com>
To: kvmarm@lists.cs.columbia.edu
Cc: linux-arm-kernel@lists.infradead.org, kernel-team@android.com,
	maz@kernel.org, Sudeep Holla <sudeep.holla@arm.com>,
	catalin.marinas@arm.com, will@kernel.org
Subject: [PATCH v4 07/19] KVM: arm64: nVHE: Don't consume host SErrors with ESB
Date: Tue, 15 Sep 2020 11:46:31 +0100	[thread overview]
Message-ID: <20200915104643.2543892-8-ascull@google.com> (raw)
In-Reply-To: <20200915104643.2543892-1-ascull@google.com>

The ESB at the start of the host vector may cause SErrors to be consumed
to DISR_EL1. However, this is not checked for the host so the SError
could go unhandled.

Remove the ESB so that SErrors are not consumed but are instead left
pending for the host to consume. __guest_enter already defers entry into
a guest if there are any SErrors pending.

Cc: James Morse <james.morse@arm.com>
Signed-off-by: Andrew Scull <ascull@google.com>
---
 arch/arm64/kvm/hyp/nvhe/host.S | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S
index 128af58d342d..da21fddcef75 100644
--- a/arch/arm64/kvm/hyp/nvhe/host.S
+++ b/arch/arm64/kvm/hyp/nvhe/host.S
@@ -25,7 +25,6 @@ SYM_FUNC_END(__hyp_do_panic)
 .macro host_el1_sync_vect
 	.align 7
 .L__vect_start\@:
-	esb
 	stp	x0, x1, [sp, #-16]!
 	mrs	x0, esr_el2
 	lsr	x0, x0, #ESR_ELx_EC_SHIFT
@@ -80,6 +79,11 @@ SYM_FUNC_END(__hyp_do_panic)
 .endm
 
 /*
+ * The host vector does not use an ESB instruction in order to avoid consuming
+ * SErrors that should only be consumed by the host. Guest entry is deferred by
+ * __guest_enter if there are any pending asynchronous exceptions so hyp will
+ * always return to the host without having consumerd host SErrors.
+ *
  * CONFIG_KVM_INDIRECT_VECTORS is not applied to the host vectors because the
  * host knows about the EL2 vectors already, and there is no point in hiding
  * them.
-- 
2.28.0.618.gf4bc123cb7-goog

_______________________________________________
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kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

WARNING: multiple messages have this Message-ID (diff)
From: Andrew Scull <ascull@google.com>
To: kvmarm@lists.cs.columbia.edu
Cc: linux-arm-kernel@lists.infradead.org, kernel-team@android.com,
	suzuki.poulose@arm.com, maz@kernel.org,
	Sudeep Holla <sudeep.holla@arm.com>,
	james.morse@arm.com, Andrew Scull <ascull@google.com>,
	catalin.marinas@arm.com, will@kernel.org,
	julien.thierry.kdev@gmail.com
Subject: [PATCH v4 07/19] KVM: arm64: nVHE: Don't consume host SErrors with ESB
Date: Tue, 15 Sep 2020 11:46:31 +0100	[thread overview]
Message-ID: <20200915104643.2543892-8-ascull@google.com> (raw)
In-Reply-To: <20200915104643.2543892-1-ascull@google.com>

The ESB at the start of the host vector may cause SErrors to be consumed
to DISR_EL1. However, this is not checked for the host so the SError
could go unhandled.

Remove the ESB so that SErrors are not consumed but are instead left
pending for the host to consume. __guest_enter already defers entry into
a guest if there are any SErrors pending.

Cc: James Morse <james.morse@arm.com>
Signed-off-by: Andrew Scull <ascull@google.com>
---
 arch/arm64/kvm/hyp/nvhe/host.S | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S
index 128af58d342d..da21fddcef75 100644
--- a/arch/arm64/kvm/hyp/nvhe/host.S
+++ b/arch/arm64/kvm/hyp/nvhe/host.S
@@ -25,7 +25,6 @@ SYM_FUNC_END(__hyp_do_panic)
 .macro host_el1_sync_vect
 	.align 7
 .L__vect_start\@:
-	esb
 	stp	x0, x1, [sp, #-16]!
 	mrs	x0, esr_el2
 	lsr	x0, x0, #ESR_ELx_EC_SHIFT
@@ -80,6 +79,11 @@ SYM_FUNC_END(__hyp_do_panic)
 .endm
 
 /*
+ * The host vector does not use an ESB instruction in order to avoid consuming
+ * SErrors that should only be consumed by the host. Guest entry is deferred by
+ * __guest_enter if there are any pending asynchronous exceptions so hyp will
+ * always return to the host without having consumerd host SErrors.
+ *
  * CONFIG_KVM_INDIRECT_VECTORS is not applied to the host vectors because the
  * host knows about the EL2 vectors already, and there is no point in hiding
  * them.
-- 
2.28.0.618.gf4bc123cb7-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  parent reply	other threads:[~2020-09-15 10:47 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-15 10:46 [PATCH v4 00/19] Introduce separate nVHE hyp context Andrew Scull
2020-09-15 10:46 ` Andrew Scull
2020-09-15 10:46 ` [PATCH v4 01/19] KVM: arm64: Remove __activate_vm wrapper Andrew Scull
2020-09-15 10:46   ` Andrew Scull
2020-09-15 10:46 ` [PATCH v4 02/19] KVM: arm64: Remove hyp_panic arguments Andrew Scull
2020-09-15 10:46   ` Andrew Scull
2020-09-15 10:46 ` [PATCH v4 03/19] KVM: arm64: Remove kvm_host_data_t typedef Andrew Scull
2020-09-15 10:46   ` Andrew Scull
2020-09-15 10:46 ` [PATCH v4 04/19] KVM: arm64: Choose hyp symbol based on context Andrew Scull
2020-09-15 10:46   ` Andrew Scull
2020-09-15 10:46 ` [PATCH v4 05/19] KVM: arm64: Save chosen hyp vector to a percpu variable Andrew Scull
2020-09-15 10:46   ` Andrew Scull
2020-09-15 10:46 ` [PATCH v4 06/19] KVM: arm64: nVHE: Use separate vector for the host Andrew Scull
2020-09-15 10:46   ` Andrew Scull
2020-09-15 10:46 ` Andrew Scull [this message]
2020-09-15 10:46   ` [PATCH v4 07/19] KVM: arm64: nVHE: Don't consume host SErrors with ESB Andrew Scull
2020-09-15 10:46 ` [PATCH v4 08/19] KVM: arm64: Introduce hyp context Andrew Scull
2020-09-15 10:46   ` Andrew Scull
2020-09-15 10:46 ` [PATCH v4 09/19] KVM: arm64: Update context references from host to hyp Andrew Scull
2020-09-15 10:46   ` Andrew Scull
2020-09-15 10:46 ` [PATCH v4 10/19] KVM: arm64: Restore hyp when panicking in guest context Andrew Scull
2020-09-15 10:46   ` Andrew Scull
2020-09-16 11:20   ` Marc Zyngier
2020-09-16 11:20     ` Marc Zyngier
2020-09-15 10:46 ` [PATCH v4 11/19] KVM: arm64: Share context save and restore macros Andrew Scull
2020-09-15 10:46   ` Andrew Scull
2020-09-15 10:46 ` [PATCH v4 12/19] KVM: arm64: nVHE: Switch to hyp context for EL2 Andrew Scull
2020-09-15 10:46   ` Andrew Scull
2020-09-16 13:14   ` Marc Zyngier
2020-09-16 13:14     ` Marc Zyngier
2020-09-15 10:46 ` [PATCH v4 13/19] KVM: arm64: nVHE: Handle hyp panics Andrew Scull
2020-09-15 10:46   ` Andrew Scull
2020-09-15 10:46 ` [PATCH v4 14/19] KVM: arm64: nVHE: Pass pointers consistently to hyp-init Andrew Scull
2020-09-15 10:46   ` Andrew Scull
2020-09-15 10:46 ` [PATCH v4 15/19] smccc: Define vendor hyp owned service call region Andrew Scull
2020-09-15 10:46   ` Andrew Scull
2020-09-15 10:46 ` [PATCH v4 16/19] smccc: Use separate variables for args and results Andrew Scull
2020-09-15 10:46   ` Andrew Scull
2020-09-15 10:46 ` [PATCH v4 17/19] KVM: arm64: nVHE: Migrate hyp interface to SMCCC Andrew Scull
2020-09-15 10:46   ` Andrew Scull
2020-09-15 10:46 ` [PATCH v4 18/19] KVM: arm64: nVHE: Migrate hyp-init " Andrew Scull
2020-09-15 10:46   ` Andrew Scull
2020-09-15 10:46 ` [PATCH v4 19/19] KVM: arm64: nVHE: Fix pointers during SMCCC convertion Andrew Scull
2020-09-15 10:46   ` Andrew Scull

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