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From: Andrew Scull <ascull@google.com>
To: kvmarm@lists.cs.columbia.edu
Cc: maz@kernel.org, kernel-team@android.com
Subject: [PATCH 31/37] KVM: arm64: Move speculative AT ISBs into context
Date: Wed, 15 Jul 2020 19:44:32 +0100
Message-ID: <20200715184438.1390996-32-ascull@google.com> (raw)
In-Reply-To: <20200715184438.1390996-1-ascull@google.com>

VHE's workaround requires an ISB between the configuration of the S2
translation and the update of HCR_EL2. It's much easier to see when and
why this is happening if it all happens at the same place in the same
file.

nVHE's workaround does not require an immediate ISB after the
configuration of the S2 translation as the necessary synchronization
happens at a later stage.

Signed-off-by: Andrew Scull <ascull@google.com>
---
 arch/arm64/include/asm/kvm_mmu.h | 7 -------
 arch/arm64/kvm/hyp/nvhe/tlb.c    | 2 +-
 arch/arm64/kvm/hyp/vhe/switch.c  | 1 +
 arch/arm64/kvm/hyp/vhe/tlb.c     | 4 ++--
 4 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 22157ded04ca..835d3fe2f781 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -596,13 +596,6 @@ static __always_inline void __load_guest_stage2(struct kvm_s2_mmu *mmu)
 {
 	write_sysreg(kern_hyp_va(mmu->kvm)->arch.vtcr, vtcr_el2);
 	write_sysreg(kvm_get_vttbr(mmu), vttbr_el2);
-
-	/*
-	 * ARM errata 1165522 and 1530923 require the actual execution of the
-	 * above before we can switch to the EL1/EL0 translation regime used by
-	 * the guest.
-	 */
-	asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_SPECULATIVE_AT));
 }
 
 #endif /* __ASSEMBLY__ */
diff --git a/arch/arm64/kvm/hyp/nvhe/tlb.c b/arch/arm64/kvm/hyp/nvhe/tlb.c
index 16fa06ff0554..2a0de9d67f00 100644
--- a/arch/arm64/kvm/hyp/nvhe/tlb.c
+++ b/arch/arm64/kvm/hyp/nvhe/tlb.c
@@ -38,7 +38,7 @@ static void __tlb_switch_to_guest(struct kvm_s2_mmu *mmu,
 
 	/* __load_guest_stage2() includes an ISB for the workaround. */
 	__load_guest_stage2(mmu);
-	asm(ALTERNATIVE("isb", "nop", ARM64_WORKAROUND_SPECULATIVE_AT));
+	isb();
 }
 
 static void __tlb_switch_to_host(struct tlb_inv_context *cxt)
diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c
index 3c475cc83a2d..04ee01774ea2 100644
--- a/arch/arm64/kvm/hyp/vhe/switch.c
+++ b/arch/arm64/kvm/hyp/vhe/switch.c
@@ -126,6 +126,7 @@ static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
 	 * (among other things).
 	 */
 	__activate_vm(vcpu->arch.hw_mmu);
+	asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_SPECULATIVE_AT));
 	__activate_traps(vcpu);
 
 	sysreg_restore_guest_state_vhe(guest_ctxt);
diff --git a/arch/arm64/kvm/hyp/vhe/tlb.c b/arch/arm64/kvm/hyp/vhe/tlb.c
index fd7895945bbc..b9abd17c1180 100644
--- a/arch/arm64/kvm/hyp/vhe/tlb.c
+++ b/arch/arm64/kvm/hyp/vhe/tlb.c
@@ -50,10 +50,10 @@ static void __tlb_switch_to_guest(struct kvm_s2_mmu *mmu,
 	 *
 	 * ARM erratum 1165522 requires some special handling (again),
 	 * as we need to make sure both stages of translation are in
-	 * place before clearing TGE. __load_guest_stage2() already
-	 * has an ISB in order to deal with this.
+	 * place before clearing TGE.
 	 */
 	__load_guest_stage2(mmu);
+	asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_SPECULATIVE_AT));
 	val = read_sysreg(hcr_el2);
 	val &= ~HCR_TGE;
 	write_sysreg(val, hcr_el2);
-- 
2.27.0.389.gc38d7665816-goog

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  parent reply index

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-15 18:44 [PATCH 00/37] Transform the host into a vCPU Andrew Scull
2020-07-15 18:44 ` [PATCH 01/37] smccc: Make constants available to assembly Andrew Scull
2020-07-15 18:44 ` [PATCH 02/37] KVM: arm64: Move clearing of vcpu debug dirty bit Andrew Scull
2020-07-15 18:44 ` [PATCH 03/37] KVM: arm64: Track running vCPU outside of the CPU context Andrew Scull
2020-07-15 18:44 ` [PATCH 04/37] KVM: arm64: nVHE: Pass pointers consistently to hyp-init Andrew Scull
2020-07-15 18:44 ` [PATCH 05/37] KVM: arm64: nVHE: Break out of the hyp-init idmap Andrew Scull
2020-07-15 18:44 ` [PATCH 06/37] KVM: arm64: Only check pending interrupts if it would trap Andrew Scull
2020-07-17 16:21   ` Marc Zyngier
2020-07-15 18:44 ` [PATCH 07/37] KVM: arm64: Separate SError detection from VAXorcism Andrew Scull
2020-07-18  9:00   ` Marc Zyngier
2020-07-20 14:13     ` Andrew Scull
2020-07-20 14:56       ` Marc Zyngier
2020-07-23  0:59         ` FW: " Renters Cancellation Requests
2020-07-20 15:40   ` Andrew Scull
2020-07-20 15:57     ` Marc Zyngier
2020-07-15 18:44 ` [PATCH 08/37] KVM: arm64: nVHE: Introduce a hyp run loop for the host Andrew Scull
2020-07-15 18:44 ` [PATCH 09/37] smccc: Cast arguments to unsigned long Andrew Scull
2020-07-15 18:44 ` [PATCH 10/37] KVM: arm64: nVHE: Migrate hyp interface to SMCCC Andrew Scull
2020-07-15 18:44 ` [PATCH 11/37] KVM: arm64: nVHE: Migrate hyp-init " Andrew Scull
2020-07-15 18:44 ` [PATCH 12/37] KVM: arm64: nVHE: Fix pointers during SMCCC convertion Andrew Scull
2020-07-15 18:44 ` [PATCH 13/37] KVM: arm64: Rename workaround 2 helpers Andrew Scull
2020-07-15 18:44 ` [PATCH 14/37] KVM: arm64: nVHE: Use __kvm_vcpu_run for the host vcpu Andrew Scull
2020-07-15 18:44 ` [PATCH 15/37] KVM: arm64: Share some context save and restore macros Andrew Scull
2020-07-15 18:44 ` [PATCH 16/37] KVM: arm64: nVHE: Handle stub HVCs in the host loop Andrew Scull
2020-07-15 18:44 ` [PATCH 17/37] KVM: arm64: nVHE: Store host sysregs in host vcpu Andrew Scull
2020-07-15 18:44 ` [PATCH 18/37] KVM: arm64: nVHE: Access pmu_events directly in kvm_host_data Andrew Scull
2020-07-15 18:44 ` [PATCH 19/37] KVM: arm64: nVHE: Drop host_ctxt argument for context switching Andrew Scull
2020-07-15 18:44 ` [PATCH 20/37] KVM: arm64: nVHE: Use host vcpu context for host debug state Andrew Scull
2020-07-15 18:44 ` [PATCH 21/37] KVM: arm64: Move host debug state from vcpu to percpu Andrew Scull
2020-07-15 18:44 ` [PATCH 22/37] KVM: arm64: nVHE: Store host's mdcr_el2 and hcr_el2 in its vcpu Andrew Scull
2020-07-15 18:44 ` [PATCH 23/37] KVM: arm64: Skip __hyp_panic and go direct to hyp_panic Andrew Scull
2020-07-15 18:44 ` [PATCH 24/37] KVM: arm64: Break apart kvm_host_data Andrew Scull
2020-07-15 18:44 ` [PATCH 25/37] KVM: arm64: nVHE: Unify sysreg state saving paths Andrew Scull
2020-07-15 18:44 ` [PATCH 26/37] KVM: arm64: nVHE: Unify 32-bit sysreg " Andrew Scull
2020-07-15 18:44 ` [PATCH 27/37] KVM: arm64: nVHE: Unify vgic save and restore Andrew Scull
2020-07-15 18:44 ` [PATCH 28/37] KVM: arm64: nVHE: Unify fpexc32 saving paths Andrew Scull
2020-07-15 18:44 ` [PATCH 29/37] KVM: arm64: nVHE: Separate the save and restore of debug state Andrew Scull
2020-07-15 18:44 ` [PATCH 30/37] KVM: arm64: nVHE: Remove MMU assumption in speculative AT workaround Andrew Scull
2020-07-15 18:44 ` Andrew Scull [this message]
2020-07-15 18:44 ` [PATCH 32/37] KVM: arm64: nVHE: Unify sysreg state restoration paths Andrew Scull
2020-07-15 18:44 ` [PATCH 33/37] KVM: arm64: Remove __activate_vm wrapper Andrew Scull
2020-07-15 18:44 ` [PATCH 34/37] KVM: arm64: nVHE: Unify timer restore paths Andrew Scull
2020-07-15 18:44 ` [PATCH 35/37] KVM: arm64: nVHE: Unify PMU event restoration paths Andrew Scull
2020-07-15 18:44 ` [PATCH 36/37] KVM: arm64: nVHE: Unify GIC PMR " Andrew Scull
2020-07-15 18:44 ` [PATCH 37/37] KVM: arm64: Separate save and restore of vcpu trap state Andrew Scull

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