From: Oliver Upton <oliver.upton@linux.dev>
To: kvmarm@lists.linux.dev
Cc: kvm@vger.kernel.org, Marc Zyngier <maz@kernel.org>,
James Morse <james.morse@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>,
Jing Zhang <jingzhangos@google.com>,
Cornelia Huck <cohuck@redhat.com>,
Oliver Upton <oliver.upton@linux.dev>
Subject: [PATCH v11 08/12] KVM: arm64: Allow userspace to change ID_AA64PFR0_EL1
Date: Tue, 3 Oct 2023 23:04:04 +0000 [thread overview]
Message-ID: <20231003230408.3405722-9-oliver.upton@linux.dev> (raw)
In-Reply-To: <20231003230408.3405722-1-oliver.upton@linux.dev>
From: Jing Zhang <jingzhangos@google.com>
Allow userspace to change the guest-visible value of the register with
some severe limitation:
- No changes to features not virtualized by KVM (AMU, MPAM, RAS)
- Short of full GICv2 emulation in kernel, hiding GICv3 from the guest
makes absolutely no sense.
- FP is effectively assumed for KVM VMs.
Signed-off-by: Jing Zhang <jingzhangos@google.com>
[oliver: restrict features that are illogical to change]
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
arch/arm64/kvm/sys_regs.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 9e31887ee0f4..24825b73d365 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2057,7 +2057,13 @@ static const struct sys_reg_desc sys_reg_descs[] = {
.get_user = get_id_reg,
.set_user = set_id_reg,
.reset = read_sanitised_id_aa64pfr0_el1,
- .val = ID_AA64PFR0_EL1_CSV2_MASK | ID_AA64PFR0_EL1_CSV3_MASK, },
+ .val = ~(ID_AA64PFR0_EL1_AMU |
+ ID_AA64PFR0_EL1_MPAM |
+ ID_AA64PFR0_EL1_SVE |
+ ID_AA64PFR0_EL1_RAS |
+ ID_AA64PFR0_EL1_GIC |
+ ID_AA64PFR0_EL1_AdvSIMD |
+ ID_AA64PFR0_EL1_FP), },
ID_SANITISED(ID_AA64PFR1_EL1),
ID_UNALLOCATED(4,2),
ID_UNALLOCATED(4,3),
--
2.42.0.609.gbb76f46606-goog
next prev parent reply other threads:[~2023-10-03 23:04 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-03 23:03 [PATCH v11 00/12] KVM: arm64: Enable 'writable' ID registers Oliver Upton
2023-10-03 23:03 ` [PATCH v11 01/12] KVM: arm64: Allow userspace to get the writable masks for feature " Oliver Upton
2023-10-03 23:03 ` [PATCH v11 02/12] KVM: arm64: Document KVM_ARM_GET_REG_WRITABLE_MASKS Oliver Upton
2023-10-03 23:03 ` [PATCH v11 03/12] KVM: arm64: Use guest ID register values for the sake of emulation Oliver Upton
2023-10-03 23:04 ` [PATCH v11 04/12] KVM: arm64: Reject attempts to set invalid debug arch version Oliver Upton
2023-10-03 23:04 ` [PATCH v11 05/12] KVM: arm64: Bump up the default KVM sanitised debug version to v8p8 Oliver Upton
2023-10-04 8:57 ` Marc Zyngier
2023-10-04 17:08 ` Oliver Upton
2023-10-04 17:46 ` Marc Zyngier
2023-10-03 23:04 ` [PATCH v11 06/12] KVM: arm64: Allow userspace to change ID_AA64ISAR{0-2}_EL1 Oliver Upton
2023-10-03 23:04 ` [PATCH v11 07/12] KVM: arm64: Allow userspace to change ID_AA64MMFR{0-2}_EL1 Oliver Upton
2023-10-03 23:04 ` Oliver Upton [this message]
2023-10-03 23:04 ` [PATCH v11 09/12] KVM: arm64: Allow userspace to change ID_AA64ZFR0_EL1 Oliver Upton
2023-10-03 23:04 ` [PATCH v11 10/12] KVM: arm64: Document vCPU feature selection UAPIs Oliver Upton
2023-10-04 9:36 ` Marc Zyngier
2023-10-04 16:52 ` Oliver Upton
2023-10-04 17:48 ` Marc Zyngier
2023-10-03 23:04 ` [PATCH v11 11/12] KVM: arm64: selftests: Import automatic generation of sysreg defs Oliver Upton
2023-10-03 23:04 ` [PATCH v11 12/12] KVM: arm64: selftests: Test for setting ID register from usersapce Oliver Upton
2023-10-04 9:40 ` [PATCH v11 00/12] KVM: arm64: Enable 'writable' ID registers Marc Zyngier
2023-10-04 16:53 ` Oliver Upton
2023-10-04 17:46 ` Oliver Upton
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=20231003230408.3405722-9-oliver.upton@linux.dev \
--to=oliver.upton@linux.dev \
--cc=cohuck@redhat.com \
--cc=james.morse@arm.com \
--cc=jingzhangos@google.com \
--cc=kvm@vger.kernel.org \
--cc=kvmarm@lists.linux.dev \
--cc=maz@kernel.org \
--cc=suzuki.poulose@arm.com \
--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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox