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From: Marc Zyngier <maz@kernel.org>
To: linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>,
	Jing Zhang <jingzhangos@google.com>,
	Prasad Sodagudi <psodagud@codeaurora.org>,
	Srinivas Ramana <sramana@codeaurora.org>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Hector Martin <marcan@marcan.st>,
	Alexandru Elisei <alexandru.elisei@arm.com>,
	James Morse <james.morse@arm.com>,
	Ajay Patil <pajay@qti.qualcomm.com>,
	kernel-team@android.com, David Brazdil <dbrazdil@google.com>,
	Will Deacon <will@kernel.org>, Ard Biesheuvel <ardb@kernel.org>,
	Julien Thierry <julien.thierry.kdev@gmail.com>
Subject: [PATCH v7 06/23] arm64: Drop early setting of MDSCR_EL2.TPMS
Date: Mon,  8 Feb 2021 09:57:15 +0000	[thread overview]
Message-ID: <20210208095732.3267263-7-maz@kernel.org> (raw)
In-Reply-To: <20210208095732.3267263-1-maz@kernel.org>

When running VHE, we set MDSCR_EL2.TPMS very early on to force
the trapping of EL1 SPE accesses to EL2.

However:
- we are running with HCR_EL2.{E2H,TGE}={1,1}, meaning that there
  is no EL1 to trap from

- before entering a guest, we call kvm_arm_setup_debug(), which
  sets MDCR_EL2_TPMS in the per-vcpu shadow mdscr_el2, which gets
  applied on entry by __activate_traps_common().

The early setting of MDSCR_EL2.TPMS is therefore useless and can
be dropped.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/include/asm/el2_setup.h | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h
index 540116de80bf..56c9e1cef180 100644
--- a/arch/arm64/include/asm/el2_setup.h
+++ b/arch/arm64/include/asm/el2_setup.h
@@ -66,9 +66,6 @@
 	mov	x0, #(MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT)
 	orr	x2, x2, x0			// If we don't have VHE, then
 						// use EL1&0 translation.
-.else
-	orr	x2, x2, #MDCR_EL2_TPMS		// For VHE, use EL2 translation
-						// and disable access from EL1
 .endif
 
 .Lskip_spe_\@:
-- 
2.29.2


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  parent reply	other threads:[~2021-02-08  9:59 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-08  9:57 [PATCH v7 00/23] arm64: Early CPU feature override, and applications to VHE, BTI and PAuth Marc Zyngier
2021-02-08  9:57 ` [PATCH v7 01/23] arm64: Fix labels in el2_setup macros Marc Zyngier
2021-02-08  9:57 ` [PATCH v7 02/23] arm64: Fix outdated TCR setup comment Marc Zyngier
2021-02-08  9:57 ` [PATCH v7 03/23] arm64: Turn the MMU-on sequence into a macro Marc Zyngier
2021-02-08  9:57 ` [PATCH v7 04/23] arm64: Provide an 'upgrade to VHE' stub hypercall Marc Zyngier
2021-02-08  9:57 ` [PATCH v7 05/23] arm64: Initialise as nVHE before switching to VHE Marc Zyngier
2021-02-08  9:57 ` Marc Zyngier [this message]
2021-02-08  9:57 ` [PATCH v7 07/23] arm64: Move VHE-specific SPE setup to mutate_to_vhe() Marc Zyngier
2021-02-08  9:57 ` [PATCH v7 08/23] arm64: Simplify init_el2_state to be non-VHE only Marc Zyngier
2021-02-08  9:57 ` [PATCH v7 09/23] arm64: Move SCTLR_EL1 initialisation to EL-agnostic code Marc Zyngier
2021-02-08  9:57 ` [PATCH v7 10/23] arm64: cpufeature: Add global feature override facility Marc Zyngier
2021-02-08  9:57 ` [PATCH v7 11/23] arm64: cpufeature: Use IDreg override in __read_sysreg_by_encoding() Marc Zyngier
2021-02-08  9:57 ` [PATCH v7 12/23] arm64: Extract early FDT mapping from kaslr_early_init() Marc Zyngier
2021-02-08  9:57 ` [PATCH v7 13/23] arm64: cpufeature: Add an early command-line cpufeature override facility Marc Zyngier
2021-02-08  9:57 ` [PATCH v7 14/23] arm64: Allow ID_AA64MMFR1_EL1.VH to be overridden from the command line Marc Zyngier
2021-02-08  9:57 ` [PATCH v7 15/23] arm64: Honor VHE being disabled from the command-line Marc Zyngier
2021-02-08  9:57 ` [PATCH v7 16/23] arm64: Add an aliasing facility for the idreg override Marc Zyngier
2021-02-08  9:57 ` [PATCH v7 17/23] arm64: Make kvm-arm.mode={nvhe, protected} an alias of id_aa64mmfr1.vh=0 Marc Zyngier
2021-02-08  9:57 ` [PATCH v7 18/23] KVM: arm64: Document HVC_VHE_RESTART stub hypercall Marc Zyngier
2021-02-08  9:57 ` [PATCH v7 19/23] arm64: Move "nokaslr" over to the early cpufeature infrastructure Marc Zyngier
2021-02-08  9:57 ` [PATCH v7 20/23] arm64: cpufeatures: Allow disabling of BTI from the command-line Marc Zyngier
2021-02-08  9:57 ` [PATCH v7 21/23] arm64: Defer enabling pointer authentication on boot core Marc Zyngier
2021-02-08  9:57 ` [PATCH v7 22/23] arm64: cpufeatures: Allow disabling of Pointer Auth from the command-line Marc Zyngier
2021-02-08  9:57 ` [PATCH v7 23/23] [DO NOT MERGE] arm64: Cope with CPUs stuck in VHE mode Marc Zyngier
2021-02-22  9:35   ` Jonathan Neuschäfer
2021-02-22  9:47     ` Marc Zyngier
2021-02-08 14:32 ` [PATCH v7 00/23] arm64: Early CPU feature override, and applications to VHE, BTI and PAuth Will Deacon
2021-02-08 14:40   ` Ard Biesheuvel
2021-02-08 15:02   ` Marc Zyngier
2021-02-08 16:30   ` Marc Zyngier

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