From: Miguel Luis <miguel.luis@oracle.com>
To: Marc Zyngier <maz@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Oliver Upton <oliver.upton@linux.dev>,
James Morse <james.morse@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"kvmarm@lists.linux.dev" <kvmarm@lists.linux.dev>
Subject: Re: [PATCH 2/3] arm64/kvm: Fine grain _EL2 system registers list that affect nested virtualization
Date: Tue, 19 Sep 2023 14:54:53 +0000 [thread overview]
Message-ID: <00087AB1-3F94-4D3B-8498-3CE3AEDFE6FA@oracle.com> (raw)
In-Reply-To: <868r93es5a.wl-maz@kernel.org>
Hi Marc,
> On 18 Sep 2023, at 09:40, Marc Zyngier <maz@kernel.org> wrote:
>
> Hi Miguel,
>
> On Wed, 13 Sep 2023 19:52:07 +0100,
> Miguel Luis <miguel.luis@oracle.com> wrote:
>>
>> Some _EL1 registers got included in the _EL2 ranges, which are not
>> affected by NV. Remove them and fine grain the ranges to exclusively
>> include the _EL2 ones.
>>
>> Signed-off-by: Miguel Luis <miguel.luis@oracle.com>
>> ---
>> arch/arm64/kvm/emulate-nested.c | 44 ++++++++++++++++++++++++++++-----
>> 1 file changed, 38 insertions(+), 6 deletions(-)
>>
>> diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c
>> index 9ced1bf0c2b7..9aa1c06abdb7 100644
>> --- a/arch/arm64/kvm/emulate-nested.c
>> +++ b/arch/arm64/kvm/emulate-nested.c
>> @@ -649,14 +649,46 @@ static const struct encoding_to_trap_config encoding_to_cgt[] __initconst = {
>> SR_TRAP(SYS_APGAKEYHI_EL1, CGT_HCR_APK),
>> /* All _EL2 registers */
>> SR_RANGE_TRAP(sys_reg(3, 4, 0, 0, 0),
>> - sys_reg(3, 4, 3, 15, 7), CGT_HCR_NV),
>> + sys_reg(3, 4, 4, 0, 1), CGT_HCR_NV),
>
> It would be good if the commit message explained that you are folding
> SPSR/ELR into the existing range. Also, please keep the two ends of
> the ranges vertically aligned.
>
OK.
>> /* Skip the SP_EL1 encoding... */
>> - SR_TRAP(SYS_SPSR_EL2, CGT_HCR_NV),
>> - SR_TRAP(SYS_ELR_EL2, CGT_HCR_NV),
>> - SR_RANGE_TRAP(sys_reg(3, 4, 4, 1, 1),
>> - sys_reg(3, 4, 10, 15, 7), CGT_HCR_NV),
>> + SR_RANGE_TRAP(sys_reg(3, 4, 4, 3, 0),
>> + sys_reg(3, 4, 10, 6, 7), CGT_HCR_NV),
>> + /* skip MECID_A0_EL2, MECID_A1_EL2, MECID_P0_EL2,
>> + * MECID_P1_EL2, MECIDR_EL2, VMECID_A_EL2,
>> + * VMECID_P_EL2.
>> + */
>
> Please follow the kernel comment format. Also, why are you skipping
> the MEC registers, but not the MPAM ones? At least indicate a
> rationale for this.
>
I’m not aware of any exceptions for MPAM registers, although there are for MEC
when HCR_EL2.NV2 is 0.
>> SR_RANGE_TRAP(sys_reg(3, 4, 12, 0, 0),
>> - sys_reg(3, 4, 14, 15, 7), CGT_HCR_NV),
>> + sys_reg(3, 4, 12, 1, 1), CGT_HCR_NV),
>> + /* ICH_AP0R<m>_EL2 */
>> + SR_RANGE_TRAP(SYS_ICH_AP0R0_EL2,
>> + SYS_ICH_AP0R3_EL2, CGT_HCR_NV),
>> + /* ICH_AP1R<m>_EL2 */
>> + SR_RANGE_TRAP(SYS_ICH_AP1R0_EL2,
>> + SYS_ICH_AP1R3_EL2, CGT_HCR_NV),
>> + SR_RANGE_TRAP(sys_reg(3, 4, 12, 9, 5),
>> + sys_reg(3, 4, 12, 11, 7), CGT_HCR_NV),
>> + /* ICH_LR<m>_EL2 */
>> + SR_TRAP(SYS_ICH_LR0_EL2, CGT_HCR_NV),
>> + SR_TRAP(SYS_ICH_LR1_EL2, CGT_HCR_NV),
>> + SR_TRAP(SYS_ICH_LR2_EL2, CGT_HCR_NV),
>> + SR_TRAP(SYS_ICH_LR3_EL2, CGT_HCR_NV),
>> + SR_TRAP(SYS_ICH_LR4_EL2, CGT_HCR_NV),
>> + SR_TRAP(SYS_ICH_LR5_EL2, CGT_HCR_NV),
>> + SR_TRAP(SYS_ICH_LR6_EL2, CGT_HCR_NV),
>> + SR_TRAP(SYS_ICH_LR7_EL2, CGT_HCR_NV),
>> + SR_TRAP(SYS_ICH_LR8_EL2, CGT_HCR_NV),
>> + SR_TRAP(SYS_ICH_LR9_EL2, CGT_HCR_NV),
>> + SR_TRAP(SYS_ICH_LR10_EL2, CGT_HCR_NV),
>> + SR_TRAP(SYS_ICH_LR11_EL2, CGT_HCR_NV),
>> + SR_TRAP(SYS_ICH_LR12_EL2, CGT_HCR_NV),
>> + SR_TRAP(SYS_ICH_LR13_EL2, CGT_HCR_NV),
>> + SR_TRAP(SYS_ICH_LR14_EL2, CGT_HCR_NV),
>> + SR_TRAP(SYS_ICH_LR15_EL2, CGT_HCR_NV),
>
> You could describe all the LRs a single range.
>
Should we skip the gap between LR7 - LR8 ?
>> + SR_RANGE_TRAP(sys_reg(3, 4, 13, 0, 1),
>> + sys_reg(3, 4, 13, 0, 7), CGT_HCR_NV),
>> + /* skip AMEVCNTVOFF0<n>_EL2 and AMEVCNTVOFF1<n>_EL2 */
>
> Why?
I didn’t find its definition TBH although these could use a single range.
Thanks,
Miguel
>
>> + SR_RANGE_TRAP(sys_reg(3, 4, 14, 0, 3),
>> + sys_reg(3, 4, 14, 5, 2), CGT_HCR_NV),
>> /* All _EL02, _EL12 registers */
>> SR_RANGE_TRAP(sys_reg(3, 5, 0, 0, 0),
>> sys_reg(3, 5, 10, 15, 7), CGT_HCR_NV),
>
> Thanks,
>
> M.
>
> --
> Without deviation from the norm, progress is not possible.
next prev parent reply other threads:[~2023-09-19 14:55 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-13 18:52 [PATCH 0/3] Fine grain sysregs allowed to trap for nested virtualization Miguel Luis
2023-09-13 18:52 ` [PATCH 1/3] arm64: Add missing _EL12 encodings Miguel Luis
2023-09-13 18:52 ` [PATCH 2/3] arm64/kvm: Fine grain _EL2 system registers list that affect nested virtualization Miguel Luis
2023-09-18 9:40 ` Marc Zyngier
2023-09-19 14:54 ` Miguel Luis [this message]
2023-09-19 16:31 ` Marc Zyngier
2023-09-13 18:52 ` [PATCH 3/3] KVM: arm64: nv: Handle all _EL02 and _EL12 registers Miguel Luis
2023-09-18 9:44 ` Marc Zyngier
2023-09-18 12:41 ` Miguel Luis
2023-09-18 12:56 ` Marc Zyngier
2023-09-25 11:04 ` Miguel Luis
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=00087AB1-3F94-4D3B-8498-3CE3AEDFE6FA@oracle.com \
--to=miguel.luis@oracle.com \
--cc=catalin.marinas@arm.com \
--cc=james.morse@arm.com \
--cc=kvmarm@lists.linux.dev \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=maz@kernel.org \
--cc=oliver.upton@linux.dev \
--cc=suzuki.poulose@arm.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 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).