From: Auger Eric <eric.auger@redhat.com>
To: Alexandru Elisei <alexandru.elisei@arm.com>,
eric.auger.pro@gmail.com, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu,
maz@kernel.org, drjones@redhat.com
Cc: james.morse@arm.com, julien.thierry.kdev@gmail.com,
suzuki.poulose@arm.com, shuah@kernel.org, pbonzini@redhat.com
Subject: Re: [PATCH 1/9] KVM: arm64: vgic-v3: Fix some error codes when setting RDIST base
Date: Thu, 14 Jan 2021 11:02:55 +0100 [thread overview]
Message-ID: <e37f1942-dcb7-3579-0aba-e131e4bd9217@redhat.com> (raw)
In-Reply-To: <fa73780d-b72b-6810-460e-5ed1057df093@arm.com>
Hi Alexandru,
On 1/6/21 5:32 PM, Alexandru Elisei wrote:
> Hi Eric,
>
> On 12/12/20 6:50 PM, Eric Auger wrote:
>> KVM_DEV_ARM_VGIC_GRP_ADDR group doc says we should return
>> -EEXIST in case the base address of the redist is already set.
>> We currently return -EINVAL.
>>
>> However we need to return -EINVAL in case a legacy REDIST address
>> is attempted to be set while REDIST_REGIONS were set. This case
>> is discriminated by looking at the count field.
>>
>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>> ---
>> arch/arm64/kvm/vgic/vgic-mmio-v3.c | 9 +++++++--
>> 1 file changed, 7 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
>> index 15a6c98ee92f..8e8a862def76 100644
>> --- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c
>> +++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
>> @@ -792,8 +792,13 @@ static int vgic_v3_insert_redist_region(struct kvm *kvm, uint32_t index,
>> int ret;
>>
>> /* single rdist region already set ?*/
>> - if (!count && !list_empty(rd_regions))
>> - return -EINVAL;
>> + if (!count && !list_empty(rd_regions)) {
>> + rdreg = list_last_entry(rd_regions,
>> + struct vgic_redist_region, list);
>> + if (rdreg->count)
>> + return -EINVAL; /* Mixing REDIST and REDIST_REGION API */
>> + return -EEXIST;
>> + }
>
> A few instructions below:
>
> if (list_empty(rd_regions)) {
> [..]
> } else {
> rdreg = list_last_entry(rd_regions,
> struct vgic_redist_region, list);
> [..]
>
> /* Cannot add an explicitly sized regions after legacy region */
> if (!rdreg->count)
> return -EINVAL;
> }
>
> Isn't this testing for the same thing, but using the opposite condition? Or am I
> misunderstanding the code (quite likely)?
the 1st test sequence handles the case where the legacy
KVM_VGIC_V3_ADDR_TYPE_REDIST is used (!count) while the second handles
the case where the REDIST_REGION is used. Nevertheless I think this can
be simplified into:
if (list_empty(rd_regions)) {
if (index != 0)
return -EINVAL;
} else {
rdreg = list_last_entry(rd_regions,
struct vgic_redist_region, list);
if ((!count) != (!rdreg->count))
return -EINVAL; /* Mix REDIST and REDIST_REGION */
if (!count)
return -EEXIST;
if (index != rdreg->index + 1)
return -EINVAL;
}
>
> Looks to me like KVM_DEV_ARM_VGIC_GRP_ADDR(KVM_VGIC_V3_ADDR_TYPE_REDIST{,_REGION})
> used to return -EEXIST (from vgic_check_ioaddr()) before commit ccc27bf5be7b7
> ("KVM: arm/arm64: Helper to register a new redistributor region") which added the
> vgic_v3_insert_redist_region() function, so bringing back the -EEXIST return code
> looks the right thing to me.
OK thank you for the detailed study.
Eric
>
> Thanks,
> Alex
>>
>> /* cross the end of memory ? */
>> if (base + size < base)
>
next prev parent reply other threads:[~2021-01-14 10:04 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-12 18:50 [PATCH 0/9] KVM/ARM: Some vgic fixes and init sequence KVM selftests Eric Auger
2020-12-12 18:50 ` [PATCH 1/9] KVM: arm64: vgic-v3: Fix some error codes when setting RDIST base Eric Auger
2021-01-06 16:32 ` Alexandru Elisei
2021-01-14 10:02 ` Auger Eric [this message]
2020-12-12 18:50 ` [PATCH 2/9] KVM: arm64: Fix KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION read Eric Auger
2021-01-06 17:12 ` Alexandru Elisei
2021-01-13 17:18 ` Auger Eric
2020-12-12 18:50 ` [PATCH 3/9] KVM: arm64: vgic-v3: Fix error handling in vgic_v3_set_redist_base() Eric Auger
2020-12-28 15:35 ` Marc Zyngier
2021-01-13 17:18 ` Auger Eric
2020-12-12 18:50 ` [PATCH 4/9] KVM: arm/arm64: vgic: Reset base address on kvm_vgic_dist_destroy() Eric Auger
2020-12-28 15:41 ` Marc Zyngier
2021-01-13 17:18 ` Auger Eric
2020-12-12 18:50 ` [PATCH 5/9] KVM: arm: move has_run_once after the map_resources Eric Auger
2021-01-12 14:55 ` Alexandru Elisei
2021-01-14 10:02 ` Auger Eric
2021-01-20 15:56 ` Alexandru Elisei
2021-03-12 17:27 ` Auger Eric
2020-12-12 18:50 ` [PATCH 6/9] docs: kvm: devices/arm-vgic-v3: enhance KVM_DEV_ARM_VGIC_CTRL_INIT doc Eric Auger
2021-01-12 15:39 ` Alexandru Elisei
2021-01-13 17:18 ` Auger Eric
2020-12-12 18:50 ` [PATCH 7/9] KVM: arm64: Simplify argument passing to vgic_uaccess_[read|write] Eric Auger
2021-01-12 16:04 ` Alexandru Elisei
2021-01-12 16:16 ` Alexandru Elisei
2021-01-13 17:18 ` Auger Eric
2020-12-12 18:50 ` [PATCH 8/9] KVM: arm64: vgic-v3: Expose GICR_TYPER.Last for userspace Eric Auger
2021-01-12 17:02 ` Alexandru Elisei
2021-01-14 10:16 ` Auger Eric
2021-01-20 16:13 ` Alexandru Elisei
2021-03-12 17:26 ` Auger Eric
2021-01-12 17:28 ` Alexandru Elisei
2021-01-12 17:48 ` Marc Zyngier
2020-12-12 18:50 ` [PATCH 9/9] KVM: selftests: aarch64/vgic-v3 init sequence tests Eric Auger
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=e37f1942-dcb7-3579-0aba-e131e4bd9217@redhat.com \
--to=eric.auger@redhat.com \
--cc=alexandru.elisei@arm.com \
--cc=drjones@redhat.com \
--cc=eric.auger.pro@gmail.com \
--cc=james.morse@arm.com \
--cc=julien.thierry.kdev@gmail.com \
--cc=kvm@vger.kernel.org \
--cc=kvmarm@lists.cs.columbia.edu \
--cc=linux-kernel@vger.kernel.org \
--cc=maz@kernel.org \
--cc=pbonzini@redhat.com \
--cc=shuah@kernel.org \
--cc=suzuki.poulose@arm.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).