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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,
	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 v2 07/20] KVM: arm64: nVHE: Don't consume host SErrors with ESB
Date: Thu, 20 Aug 2020 11:34:33 +0100	[thread overview]
Message-ID: <20200820103446.959000-8-ascull@google.com> (raw)
In-Reply-To: <20200820103446.959000-1-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.

Fixes: 0e5b9c085dce ("KVM: arm64: Consume pending SError as early as possible")
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 9c96b9a3b71d..5a7380c342c8 100644
--- a/arch/arm64/kvm/hyp/nvhe/host.S
+++ b/arch/arm64/kvm/hyp/nvhe/host.S
@@ -24,7 +24,6 @@ SYM_FUNC_END(__hyp_do_panic)
 
 .macro valid_host_el1_sync_vect
 	.align 7
-	esb
 	stp	x0, x1, [sp, #-16]!
 
 	mrs	x0, esr_el2
@@ -77,6 +76,11 @@ 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 vector because the
  * host already knows the address of hyp by virtue of loading it there.
  */
-- 
2.28.0.220.ged08abb693-goog


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  parent reply	other threads:[~2020-08-20 10:38 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-20 10:34 [PATCH v2 00/20] Introduce separate nVHE hyp context Andrew Scull
2020-08-20 10:34 ` [PATCH v2 01/20] KVM: arm64: Remove __activate_vm wrapper Andrew Scull
2020-08-20 10:34 ` [PATCH v2 02/20] KVM: arm64: Remove hyp_panic arguments Andrew Scull
2020-08-20 10:34 ` [PATCH v2 03/20] KVM: arm64: Remove kvm_host_data_t typedef Andrew Scull
2020-08-20 10:34 ` [PATCH v2 04/20] KVM: arm64: Restrict symbol aliasing to outside nVHE Andrew Scull
2020-08-20 10:34 ` [PATCH v2 05/20] KVM: arm64: Save chosen hyp vector to a percpu variable Andrew Scull
2020-08-20 10:34 ` [PATCH v2 06/20] KVM: arm64: nVHE: Use separate vector for the host Andrew Scull
2020-08-20 10:34 ` Andrew Scull [this message]
2020-08-20 10:34 ` [PATCH v2 08/20] KVM: arm64: Preserve host DISR_EL1 Andrew Scull
2020-08-20 10:34 ` [PATCH v2 09/20] KVM: arm64: Introduce hyp context Andrew Scull
2020-08-20 10:34 ` [PATCH v2 10/20] KVM: arm64: Update context references from host to hyp Andrew Scull
2020-08-20 10:34 ` [PATCH v2 11/20] KVM: arm64: Restore hyp when panicking in guest context Andrew Scull
2020-08-20 10:34 ` [PATCH v2 12/20] KVM: arm64: Share context save and restore macros Andrew Scull
2020-08-20 10:34 ` [PATCH v2 13/20] KVM: arm64: nVHE: Switch to hyp context for EL2 Andrew Scull
2020-08-20 10:34 ` [PATCH v2 14/20] KVM: arm64: nVHE: Handle hyp panics Andrew Scull
2020-08-20 10:34 ` [PATCH v2 15/20] smccc: Cast arguments to unsigned long Andrew Scull
2020-08-20 10:34 ` [PATCH v2 16/20] KVM: arm64: nVHE: Pass pointers consistently to hyp-init Andrew Scull
2020-08-20 10:34 ` [PATCH v2 17/20] KVM: arm64: nVHE: Migrate hyp interface to SMCCC Andrew Scull
2020-08-20 10:34 ` [PATCH v2 18/20] KVM: arm64: nVHE: Migrate hyp-init " Andrew Scull
2020-08-20 10:34 ` [PATCH v2 19/20] KVM: arm64: nVHE: Fix pointers during SMCCC convertion Andrew Scull
2020-08-20 10:34 ` [PATCH v2 20/20] KVM: arm64: nVHE: Handle stub HVCs in the host loop Andrew Scull

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