All of lore.kernel.org
 help / color / mirror / Atom feed
From: Marc Zyngier <maz@kernel.org>
To: kvmarm@lists.linux.dev, kvm@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Cc: James Morse <james.morse@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Oliver Upton <oliver.upton@linux.dev>,
	Zenghui Yu <yuzenghui@huawei.com>,
	Quentin Perret <qperret@google.com>,
	Will Deacon <will@kernel.org>, Fuad Tabba <tabba@google.com>
Subject: [PATCH v2 01/17] KVM: arm64: Drop is_kernel_in_hyp_mode() from __invalidate_icache_guest_page()
Date: Fri, 26 May 2023 15:33:32 +0100	[thread overview]
Message-ID: <20230526143348.4072074-2-maz@kernel.org> (raw)
In-Reply-To: <20230526143348.4072074-1-maz@kernel.org>

It is pretty obvious that is_kernel_in_hyp_mode() doesn't make much
sense in the hypervisor part of KVM, and should be reserved to the
kernel side.

However, mem_protect.c::invalidate_icache_guest_page() calls into
__invalidate_icache_guest_page(), which uses is_kernel_in_hyp_mode().
Given that this is part of the pKVM side of the hypervisor, this
helper can only return true.

Nothing goes really bad, but __invalidate_icache_guest_page() could
spell out what the actual check is: we cannot invalidate the cache
if the i-cache is VPIPT and we're running at EL1.

Drop the is_kernel_in_hyp_mode() check for an explicit check against
CurrentEL being EL1 or not.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/include/asm/kvm_mmu.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 27e63c111f78..c8113b931263 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -227,7 +227,8 @@ static inline void __invalidate_icache_guest_page(void *va, size_t size)
 	if (icache_is_aliasing()) {
 		/* any kind of VIPT cache */
 		icache_inval_all_pou();
-	} else if (is_kernel_in_hyp_mode() || !icache_is_vpipt()) {
+	} else if (read_sysreg(CurrentEL) != CurrentEL_EL1 ||
+		   !icache_is_vpipt()) {
 		/* PIPT or VPIPT at EL2 (see comment in __kvm_tlb_flush_vmid_ipa) */
 		icache_inval_pou((unsigned long)va, (unsigned long)va + size);
 	}
-- 
2.34.1


WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: kvmarm@lists.linux.dev, kvm@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Cc: James Morse <james.morse@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Oliver Upton <oliver.upton@linux.dev>,
	Zenghui Yu <yuzenghui@huawei.com>,
	Quentin Perret <qperret@google.com>,
	Will Deacon <will@kernel.org>, Fuad Tabba <tabba@google.com>
Subject: [PATCH v2 01/17] KVM: arm64: Drop is_kernel_in_hyp_mode() from __invalidate_icache_guest_page()
Date: Fri, 26 May 2023 15:33:32 +0100	[thread overview]
Message-ID: <20230526143348.4072074-2-maz@kernel.org> (raw)
In-Reply-To: <20230526143348.4072074-1-maz@kernel.org>

It is pretty obvious that is_kernel_in_hyp_mode() doesn't make much
sense in the hypervisor part of KVM, and should be reserved to the
kernel side.

However, mem_protect.c::invalidate_icache_guest_page() calls into
__invalidate_icache_guest_page(), which uses is_kernel_in_hyp_mode().
Given that this is part of the pKVM side of the hypervisor, this
helper can only return true.

Nothing goes really bad, but __invalidate_icache_guest_page() could
spell out what the actual check is: we cannot invalidate the cache
if the i-cache is VPIPT and we're running at EL1.

Drop the is_kernel_in_hyp_mode() check for an explicit check against
CurrentEL being EL1 or not.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/include/asm/kvm_mmu.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 27e63c111f78..c8113b931263 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -227,7 +227,8 @@ static inline void __invalidate_icache_guest_page(void *va, size_t size)
 	if (icache_is_aliasing()) {
 		/* any kind of VIPT cache */
 		icache_inval_all_pou();
-	} else if (is_kernel_in_hyp_mode() || !icache_is_vpipt()) {
+	} else if (read_sysreg(CurrentEL) != CurrentEL_EL1 ||
+		   !icache_is_vpipt()) {
 		/* PIPT or VPIPT at EL2 (see comment in __kvm_tlb_flush_vmid_ipa) */
 		icache_inval_pou((unsigned long)va, (unsigned long)va + size);
 	}
-- 
2.34.1


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

  reply	other threads:[~2023-05-26 14:33 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-26 14:33 [PATCH v2 00/17] KVM: arm64: Allow using VHE in the nVHE hypervisor Marc Zyngier
2023-05-26 14:33 ` Marc Zyngier
2023-05-26 14:33 ` Marc Zyngier [this message]
2023-05-26 14:33   ` [PATCH v2 01/17] KVM: arm64: Drop is_kernel_in_hyp_mode() from __invalidate_icache_guest_page() Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 02/17] arm64: Prevent the use of is_kernel_in_hyp_mode() in hypervisor code Marc Zyngier
2023-05-26 14:33   ` Marc Zyngier
2023-05-30 19:54   ` Oliver Upton
2023-05-30 19:54     ` Oliver Upton
2023-05-31  7:17     ` Marc Zyngier
2023-05-31  7:17       ` Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 03/17] arm64: Turn kaslr_feature_override into a generic SW feature override Marc Zyngier
2023-05-26 14:33   ` Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 04/17] arm64: Add KVM_HVHE capability and has_hvhe() predicate Marc Zyngier
2023-05-26 14:33   ` Marc Zyngier
2023-06-01  7:06   ` Oliver Upton
2023-06-01  7:06     ` Oliver Upton
2023-06-01 12:27     ` Marc Zyngier
2023-06-01 12:27       ` Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 05/17] arm64: Don't enable VHE for the kernel if OVERRIDE_HVHE is set Marc Zyngier
2023-05-26 14:33   ` Marc Zyngier
2023-06-01  7:32   ` Oliver Upton
2023-06-01  7:32     ` Oliver Upton
2023-06-01 12:48     ` Marc Zyngier
2023-06-01 12:48       ` Marc Zyngier
2023-06-01 20:10       ` Oliver Upton
2023-06-01 20:10         ` Oliver Upton
2023-05-26 14:33 ` [PATCH v2 06/17] arm64: Allow EL1 physical timer access when running VHE Marc Zyngier
2023-05-26 14:33   ` Marc Zyngier
2023-06-01  6:34   ` Oliver Upton
2023-06-01  6:34     ` Oliver Upton
2023-06-01 11:59     ` Marc Zyngier
2023-06-01 11:59       ` Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 07/17] arm64: Use CPACR_EL1 format to set CPTR_EL2 when E2H is set Marc Zyngier
2023-05-26 14:33   ` Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 08/17] KVM: arm64: Remove alternatives from sysreg accessors in VHE hypervisor context Marc Zyngier
2023-05-26 14:33   ` Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 09/17] KVM: arm64: Key use of VHE instructions in nVHE code off ARM64_KVM_HVHE Marc Zyngier
2023-05-26 14:33   ` Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 10/17] KVM: arm64: Force HCR_EL2.E2H when ARM64_KVM_HVHE is set Marc Zyngier
2023-05-26 14:33   ` Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 11/17] KVM: arm64: Disable TTBR1_EL2 when using ARM64_KVM_HVHE Marc Zyngier
2023-05-26 14:33   ` Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 12/17] KVM: arm64: Adjust EL2 stage-1 leaf AP bits when ARM64_KVM_HVHE is set Marc Zyngier
2023-05-26 14:33   ` Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 13/17] KVM: arm64: Rework CPTR_EL2 programming for HVHE configuration Marc Zyngier
2023-05-26 14:33   ` Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 14/17] KVM: arm64: Program the timer traps with VHE layout in hVHE mode Marc Zyngier
2023-05-26 14:33   ` Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 15/17] KVM: arm64: Force HCR_E2H in guest context when ARM64_KVM_HVHE is set Marc Zyngier
2023-05-26 14:33   ` Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 16/17] arm64: Allow arm64_sw.hvhe on command line Marc Zyngier
2023-05-26 14:33   ` Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 17/17] KVM: arm64: Terrible timer hack for M1 with hVHE Marc Zyngier
2023-05-26 14:33   ` Marc Zyngier

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20230526143348.4072074-2-maz@kernel.org \
    --to=maz@kernel.org \
    --cc=james.morse@arm.com \
    --cc=kvm@vger.kernel.org \
    --cc=kvmarm@lists.linux.dev \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=oliver.upton@linux.dev \
    --cc=qperret@google.com \
    --cc=suzuki.poulose@arm.com \
    --cc=tabba@google.com \
    --cc=will@kernel.org \
    --cc=yuzenghui@huawei.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.