From: Catalin Marinas <catalin.marinas@arm.com>
To: ankita@nvidia.com
Cc: jgg@nvidia.com, maz@kernel.org, oliver.upton@linux.dev,
joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com,
will@kernel.org, ryan.roberts@arm.com, shahuang@redhat.com,
lpieralisi@kernel.org, david@redhat.com, ddutile@redhat.com,
seanjc@google.com, aniketa@nvidia.com, cjia@nvidia.com,
kwankhede@nvidia.com, kjaju@nvidia.com, targupta@nvidia.com,
vsethi@nvidia.com, acurrid@nvidia.com, apopple@nvidia.com,
jhubbard@nvidia.com, danw@nvidia.com, zhiw@nvidia.com,
mochs@nvidia.com, udhoke@nvidia.com, dnigam@nvidia.com,
alex.williamson@redhat.com, sebastianene@google.com,
coltonlewis@google.com, kevin.tian@intel.com, yi.l.liu@intel.com,
ardb@kernel.org, akpm@linux-foundation.org, gshan@redhat.com,
linux-mm@kvack.org, tabba@google.com, qperret@google.com,
kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, maobibo@loongson.cn
Subject: Re: [PATCH v7 1/5] KVM: arm64: Rename symbols to reflect whether CMO may be used
Date: Wed, 18 Jun 2025 15:28:46 +0100 [thread overview]
Message-ID: <aFLNHvCdz3v6XrCr@arm.com> (raw)
In-Reply-To: <20250618065541.50049-2-ankita@nvidia.com>
On Wed, Jun 18, 2025 at 06:55:37AM +0000, ankita@nvidia.com wrote:
> From: Ankit Agrawal <ankita@nvidia.com>
>
> Currently, the kvm_is_device_pfn() detects if the memory is kernel
> mapped. It thus implies whether KVM can use Cache Maintenance
> Operations (CMOs) on that PFN. Rename the function to reflect this.
>
> Additionally, the "device" variable is effectively trying to setup the S2
> to prevent CMOs. Calling it 'disable_cmo' would make this code clearer.
I'm not sure CMOs is the only reason. Another is to prevent the guest
from mapping device memory as something other than Device with
possible implications for external aborts.
--
Catalin
next prev parent reply other threads:[~2025-06-18 14:28 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-18 6:55 [PATCH v7 0/5] KVM: arm64: Map GPU device memory as cacheable ankita
2025-06-18 6:55 ` [PATCH v7 1/5] KVM: arm64: Rename symbols to reflect whether CMO may be used ankita
2025-06-18 14:28 ` Catalin Marinas [this message]
2025-06-18 14:35 ` Catalin Marinas
2025-06-19 2:22 ` Ankit Agrawal
2025-06-18 6:55 ` [PATCH v7 2/5] KVM: arm64: Block cacheable PFNMAP mapping ankita
2025-06-18 15:46 ` Catalin Marinas
2025-06-19 2:21 ` Ankit Agrawal
2025-06-18 6:55 ` [PATCH v7 3/5] KVM: arm64: New function to determine hardware cache management support ankita
2025-06-18 16:12 ` Catalin Marinas
2025-06-18 6:55 ` [PATCH v7 4/5] KVM: arm64: Allow cacheable stage 2 mapping using VMA flags ankita
2025-06-18 16:34 ` Catalin Marinas
2025-06-18 16:38 ` Jason Gunthorpe
2025-06-19 12:14 ` Ankit Agrawal
2025-06-19 14:16 ` Jason Gunthorpe
2025-06-19 16:03 ` Donald Dutile
2025-06-19 16:46 ` Ankit Agrawal
2025-06-18 6:55 ` [PATCH v7 5/5] KVM: arm64: Expose new KVM cap for cacheable PFNMAP ankita
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