From: Marc Zyngier <maz@kernel.org>
To: kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org
Cc: dave.martin@arm.com, daniel.kiss@arm.com,
Will Deacon <will@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
James Morse <james.morse@arm.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
broonie@kernel.org, ascull@google.com, qperret@google.com,
kernel-team@android.com
Subject: [PATCH v2 09/11] KVM: arm64: Trap host SVE accesses when the FPSIMD state is dirty
Date: Thu, 18 Mar 2021 12:25:30 +0000 [thread overview]
Message-ID: <20210318122532.505263-10-maz@kernel.org> (raw)
In-Reply-To: <20210318122532.505263-1-maz@kernel.org>
ZCR_EL2 controls the upper bound for ZCR_EL1, and is set to
a potentially lower limit when the guest uses SVE. In order
to restore the SVE state on the EL1 host, we must first
reset ZCR_EL2 to its original value.
To make it as lazy as possible on the EL1 host side, set
the SVE trapping in place when returning exiting from
the guest. On the first EL1 access to SVE, ZCR_EL2 will
be restored to its full glory.
Suggested-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/hyp/nvhe/hyp-main.c | 4 ++++
arch/arm64/kvm/hyp/nvhe/switch.c | 9 +++++++--
2 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index f012f8665ecc..8d04d69edd15 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -177,6 +177,10 @@ void handle_trap(struct kvm_cpu_context *host_ctxt)
case ESR_ELx_EC_SMC64:
handle_host_smc(host_ctxt);
break;
+ case ESR_ELx_EC_SVE:
+ sve_cond_update_zcr_vq(ZCR_ELx_LEN_MASK, SYS_ZCR_EL2);
+ sysreg_clear_set(cptr_el2, CPTR_EL2_TZ, 0);
+ break;
default:
hyp_panic();
}
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index f3d0e9eca56c..60adc7ff4caa 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -68,7 +68,7 @@ static void __activate_traps(struct kvm_vcpu *vcpu)
static void __deactivate_traps(struct kvm_vcpu *vcpu)
{
extern char __kvm_hyp_host_vector[];
- u64 mdcr_el2;
+ u64 mdcr_el2, cptr;
___deactivate_traps(vcpu);
@@ -101,7 +101,12 @@ static void __deactivate_traps(struct kvm_vcpu *vcpu)
write_sysreg(HCR_HOST_NVHE_PROTECTED_FLAGS, hcr_el2);
else
write_sysreg(HCR_HOST_NVHE_FLAGS, hcr_el2);
- write_sysreg(CPTR_EL2_DEFAULT, cptr_el2);
+
+ cptr = CPTR_EL2_DEFAULT;
+ if (vcpu_has_sve(vcpu) && (vcpu->arch.flags & KVM_ARM64_FP_ENABLED))
+ cptr |= CPTR_EL2_TZ;
+
+ write_sysreg(cptr, cptr_el2);
write_sysreg(__kvm_hyp_host_vector, vbar_el2);
}
--
2.29.2
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-03-18 12:29 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-18 12:25 [PATCH v2 00/11] KVM: arm64: Enable SVE support on nVHE systems Marc Zyngier
2021-03-18 12:25 ` [PATCH v2 01/11] KVM: arm64: Provide KVM's own save/restore SVE primitives Marc Zyngier
2021-03-18 12:25 ` [PATCH v2 02/11] KVM: arm64: Use {read, write}_sysreg_el1 to access ZCR_EL1 Marc Zyngier
2021-03-18 12:25 ` [PATCH v2 03/11] KVM: arm64: Let vcpu_sve_pffr() handle HYP VAs Marc Zyngier
2021-03-18 12:25 ` [PATCH v2 04/11] KVM: arm64: Introduce vcpu_sve_vq() helper Marc Zyngier
2021-03-18 12:25 ` [PATCH v2 05/11] arm64: sve: Provide a conditional update accessor for ZCR_ELx Marc Zyngier
2021-03-18 13:32 ` Will Deacon
2021-03-19 16:42 ` Mark Brown
2021-03-19 16:51 ` Marc Zyngier
2021-03-19 16:58 ` Mark Brown
2021-03-18 12:25 ` [PATCH v2 06/11] KVM: arm64: Rework SVE host-save/guest-restore Marc Zyngier
2021-03-18 13:34 ` Will Deacon
2021-03-18 12:25 ` [PATCH v2 07/11] KVM: arm64: Map SVE context at EL2 when available Marc Zyngier
2021-03-18 13:35 ` Will Deacon
2021-03-18 12:25 ` [PATCH v2 08/11] KVM: arm64: Save guest's ZCR_EL1 before saving the FPSIMD state Marc Zyngier
2021-03-18 12:25 ` Marc Zyngier [this message]
2021-03-18 14:11 ` [PATCH v2 09/11] KVM: arm64: Trap host SVE accesses when the FPSIMD state is dirty Will Deacon
2021-03-18 14:29 ` Marc Zyngier
2021-03-18 18:40 ` Marc Zyngier
2021-03-18 12:25 ` [PATCH v2 10/11] KVM: arm64: Save/restore SVE state for nVHE Marc Zyngier
2021-03-18 14:13 ` Will Deacon
2021-03-18 14:32 ` Marc Zyngier
2021-03-18 12:25 ` [PATCH v2 11/11] KVM: arm64: Enable SVE support " Marc Zyngier
2021-03-19 17:53 ` [PATCH v2 00/11] KVM: arm64: Enable SVE support on nVHE systems Mark Brown
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=20210318122532.505263-10-maz@kernel.org \
--to=maz@kernel.org \
--cc=ascull@google.com \
--cc=broonie@kernel.org \
--cc=catalin.marinas@arm.com \
--cc=daniel.kiss@arm.com \
--cc=dave.martin@arm.com \
--cc=james.morse@arm.com \
--cc=julien.thierry.kdev@gmail.com \
--cc=kernel-team@android.com \
--cc=kvm@vger.kernel.org \
--cc=kvmarm@lists.cs.columbia.edu \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=qperret@google.com \
--cc=suzuki.poulose@arm.com \
--cc=will@kernel.org \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).