From: Catalin Marinas <catalin.marinas@arm.com>
To: Steven Price <steven.price@arm.com>
Cc: Marc Zyngier <maz@kernel.org>, Will Deacon <will@kernel.org>,
James Morse <james.morse@arm.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, Dave Martin <Dave.Martin@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Thomas Gleixner <tglx@linutronix.de>,
qemu-devel@nongnu.org, Juan Quintela <quintela@redhat.com>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
Richard Henderson <richard.henderson@linaro.org>,
Peter Maydell <peter.maydell@linaro.org>,
Haibo Xu <Haibo.Xu@arm.com>, Andrew Jones <drjones@redhat.com>
Subject: Re: [PATCH v13 7/8] KVM: arm64: ioctl to fetch/store tags in a guest
Date: Thu, 3 Jun 2021 18:13:37 +0100 [thread overview]
Message-ID: <20210603171336.GH20338@arm.com> (raw)
In-Reply-To: <20210524104513.13258-8-steven.price@arm.com>
On Mon, May 24, 2021 at 11:45:12AM +0100, Steven Price wrote:
> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
> index 24223adae150..b3edde68bc3e 100644
> --- a/arch/arm64/include/uapi/asm/kvm.h
> +++ b/arch/arm64/include/uapi/asm/kvm.h
> @@ -184,6 +184,17 @@ struct kvm_vcpu_events {
> __u32 reserved[12];
> };
>
> +struct kvm_arm_copy_mte_tags {
> + __u64 guest_ipa;
> + __u64 length;
> + void __user *addr;
> + __u64 flags;
> + __u64 reserved[2];
> +};
> +
> +#define KVM_ARM_TAGS_TO_GUEST 0
> +#define KVM_ARM_TAGS_FROM_GUEST 1
> +
> /* If you need to interpret the index values, here is the key: */
> #define KVM_REG_ARM_COPROC_MASK 0x000000000FFF0000
> #define KVM_REG_ARM_COPROC_SHIFT 16
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index e89a5e275e25..baa33359e477 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -1345,6 +1345,13 @@ long kvm_arch_vm_ioctl(struct file *filp,
>
> return 0;
> }
> + case KVM_ARM_MTE_COPY_TAGS: {
> + struct kvm_arm_copy_mte_tags copy_tags;
> +
> + if (copy_from_user(©_tags, argp, sizeof(copy_tags)))
> + return -EFAULT;
> + return kvm_vm_ioctl_mte_copy_tags(kvm, ©_tags);
> + }
I wonder whether we need an update of the user structure following a
fault, like how much was copied etc. In case of an error, some tags were
copied and the VMM may want to skip the page before continuing. But here
there's no such information provided.
On the ptrace interface, we return 0 on the syscall if any bytes were
copied and update iov_len to such number. Maybe you want to still return
an error here but updating copy_tags.length would be nice (and, of
course, a copy_to_user() back).
--
Catalin
WARNING: multiple messages have this Message-ID (diff)
From: Catalin Marinas <catalin.marinas@arm.com>
To: Steven Price <steven.price@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
Peter Maydell <peter.maydell@linaro.org>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
Andrew Jones <drjones@redhat.com>, Haibo Xu <Haibo.Xu@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
qemu-devel@nongnu.org, Marc Zyngier <maz@kernel.org>,
Juan Quintela <quintela@redhat.com>,
Richard Henderson <richard.henderson@linaro.org>,
linux-kernel@vger.kernel.org, Dave Martin <Dave.Martin@arm.com>,
James Morse <james.morse@arm.com>,
linux-arm-kernel@lists.infradead.org,
Thomas Gleixner <tglx@linutronix.de>,
Will Deacon <will@kernel.org>,
kvmarm@lists.cs.columbia.edu,
Julien Thierry <julien.thierry.kdev@gmail.com>
Subject: Re: [PATCH v13 7/8] KVM: arm64: ioctl to fetch/store tags in a guest
Date: Thu, 3 Jun 2021 18:13:37 +0100 [thread overview]
Message-ID: <20210603171336.GH20338@arm.com> (raw)
In-Reply-To: <20210524104513.13258-8-steven.price@arm.com>
On Mon, May 24, 2021 at 11:45:12AM +0100, Steven Price wrote:
> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
> index 24223adae150..b3edde68bc3e 100644
> --- a/arch/arm64/include/uapi/asm/kvm.h
> +++ b/arch/arm64/include/uapi/asm/kvm.h
> @@ -184,6 +184,17 @@ struct kvm_vcpu_events {
> __u32 reserved[12];
> };
>
> +struct kvm_arm_copy_mte_tags {
> + __u64 guest_ipa;
> + __u64 length;
> + void __user *addr;
> + __u64 flags;
> + __u64 reserved[2];
> +};
> +
> +#define KVM_ARM_TAGS_TO_GUEST 0
> +#define KVM_ARM_TAGS_FROM_GUEST 1
> +
> /* If you need to interpret the index values, here is the key: */
> #define KVM_REG_ARM_COPROC_MASK 0x000000000FFF0000
> #define KVM_REG_ARM_COPROC_SHIFT 16
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index e89a5e275e25..baa33359e477 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -1345,6 +1345,13 @@ long kvm_arch_vm_ioctl(struct file *filp,
>
> return 0;
> }
> + case KVM_ARM_MTE_COPY_TAGS: {
> + struct kvm_arm_copy_mte_tags copy_tags;
> +
> + if (copy_from_user(©_tags, argp, sizeof(copy_tags)))
> + return -EFAULT;
> + return kvm_vm_ioctl_mte_copy_tags(kvm, ©_tags);
> + }
I wonder whether we need an update of the user structure following a
fault, like how much was copied etc. In case of an error, some tags were
copied and the VMM may want to skip the page before continuing. But here
there's no such information provided.
On the ptrace interface, we return 0 on the syscall if any bytes were
copied and update iov_len to such number. Maybe you want to still return
an error here but updating copy_tags.length would be nice (and, of
course, a copy_to_user() back).
--
Catalin
WARNING: multiple messages have this Message-ID (diff)
From: Catalin Marinas <catalin.marinas@arm.com>
To: Steven Price <steven.price@arm.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>,
qemu-devel@nongnu.org, Marc Zyngier <maz@kernel.org>,
Juan Quintela <quintela@redhat.com>,
Richard Henderson <richard.henderson@linaro.org>,
linux-kernel@vger.kernel.org, Dave Martin <Dave.Martin@arm.com>,
linux-arm-kernel@lists.infradead.org,
Thomas Gleixner <tglx@linutronix.de>,
Will Deacon <will@kernel.org>,
kvmarm@lists.cs.columbia.edu
Subject: Re: [PATCH v13 7/8] KVM: arm64: ioctl to fetch/store tags in a guest
Date: Thu, 3 Jun 2021 18:13:37 +0100 [thread overview]
Message-ID: <20210603171336.GH20338@arm.com> (raw)
In-Reply-To: <20210524104513.13258-8-steven.price@arm.com>
On Mon, May 24, 2021 at 11:45:12AM +0100, Steven Price wrote:
> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
> index 24223adae150..b3edde68bc3e 100644
> --- a/arch/arm64/include/uapi/asm/kvm.h
> +++ b/arch/arm64/include/uapi/asm/kvm.h
> @@ -184,6 +184,17 @@ struct kvm_vcpu_events {
> __u32 reserved[12];
> };
>
> +struct kvm_arm_copy_mte_tags {
> + __u64 guest_ipa;
> + __u64 length;
> + void __user *addr;
> + __u64 flags;
> + __u64 reserved[2];
> +};
> +
> +#define KVM_ARM_TAGS_TO_GUEST 0
> +#define KVM_ARM_TAGS_FROM_GUEST 1
> +
> /* If you need to interpret the index values, here is the key: */
> #define KVM_REG_ARM_COPROC_MASK 0x000000000FFF0000
> #define KVM_REG_ARM_COPROC_SHIFT 16
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index e89a5e275e25..baa33359e477 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -1345,6 +1345,13 @@ long kvm_arch_vm_ioctl(struct file *filp,
>
> return 0;
> }
> + case KVM_ARM_MTE_COPY_TAGS: {
> + struct kvm_arm_copy_mte_tags copy_tags;
> +
> + if (copy_from_user(©_tags, argp, sizeof(copy_tags)))
> + return -EFAULT;
> + return kvm_vm_ioctl_mte_copy_tags(kvm, ©_tags);
> + }
I wonder whether we need an update of the user structure following a
fault, like how much was copied etc. In case of an error, some tags were
copied and the VMM may want to skip the page before continuing. But here
there's no such information provided.
On the ptrace interface, we return 0 on the syscall if any bytes were
copied and update iov_len to such number. Maybe you want to still return
an error here but updating copy_tags.length would be nice (and, of
course, a copy_to_user() back).
--
Catalin
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
WARNING: multiple messages have this Message-ID (diff)
From: Catalin Marinas <catalin.marinas@arm.com>
To: Steven Price <steven.price@arm.com>
Cc: Marc Zyngier <maz@kernel.org>, Will Deacon <will@kernel.org>,
James Morse <james.morse@arm.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, Dave Martin <Dave.Martin@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Thomas Gleixner <tglx@linutronix.de>,
qemu-devel@nongnu.org, Juan Quintela <quintela@redhat.com>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
Richard Henderson <richard.henderson@linaro.org>,
Peter Maydell <peter.maydell@linaro.org>,
Haibo Xu <Haibo.Xu@arm.com>, Andrew Jones <drjones@redhat.com>
Subject: Re: [PATCH v13 7/8] KVM: arm64: ioctl to fetch/store tags in a guest
Date: Thu, 3 Jun 2021 18:13:37 +0100 [thread overview]
Message-ID: <20210603171336.GH20338@arm.com> (raw)
In-Reply-To: <20210524104513.13258-8-steven.price@arm.com>
On Mon, May 24, 2021 at 11:45:12AM +0100, Steven Price wrote:
> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
> index 24223adae150..b3edde68bc3e 100644
> --- a/arch/arm64/include/uapi/asm/kvm.h
> +++ b/arch/arm64/include/uapi/asm/kvm.h
> @@ -184,6 +184,17 @@ struct kvm_vcpu_events {
> __u32 reserved[12];
> };
>
> +struct kvm_arm_copy_mte_tags {
> + __u64 guest_ipa;
> + __u64 length;
> + void __user *addr;
> + __u64 flags;
> + __u64 reserved[2];
> +};
> +
> +#define KVM_ARM_TAGS_TO_GUEST 0
> +#define KVM_ARM_TAGS_FROM_GUEST 1
> +
> /* If you need to interpret the index values, here is the key: */
> #define KVM_REG_ARM_COPROC_MASK 0x000000000FFF0000
> #define KVM_REG_ARM_COPROC_SHIFT 16
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index e89a5e275e25..baa33359e477 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -1345,6 +1345,13 @@ long kvm_arch_vm_ioctl(struct file *filp,
>
> return 0;
> }
> + case KVM_ARM_MTE_COPY_TAGS: {
> + struct kvm_arm_copy_mte_tags copy_tags;
> +
> + if (copy_from_user(©_tags, argp, sizeof(copy_tags)))
> + return -EFAULT;
> + return kvm_vm_ioctl_mte_copy_tags(kvm, ©_tags);
> + }
I wonder whether we need an update of the user structure following a
fault, like how much was copied etc. In case of an error, some tags were
copied and the VMM may want to skip the page before continuing. But here
there's no such information provided.
On the ptrace interface, we return 0 on the syscall if any bytes were
copied and update iov_len to such number. Maybe you want to still return
an error here but updating copy_tags.length would be nice (and, of
course, a copy_to_user() back).
--
Catalin
_______________________________________________
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:[~2021-06-03 17:18 UTC|newest]
Thread overview: 92+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-24 10:45 [PATCH v13 0/8] MTE support for KVM guest Steven Price
2021-05-24 10:45 ` Steven Price
2021-05-24 10:45 ` Steven Price
2021-05-24 10:45 ` Steven Price
2021-05-24 10:45 ` [PATCH v13 1/8] arm64: mte: Handle race when synchronising tags Steven Price
2021-05-24 10:45 ` Steven Price
2021-05-24 10:45 ` Steven Price
2021-05-24 10:45 ` Steven Price
2021-05-24 10:45 ` [PATCH v13 2/8] arm64: Handle MTE tags zeroing in __alloc_zeroed_user_highpage() Steven Price
2021-05-24 10:45 ` Steven Price
2021-05-24 10:45 ` Steven Price
2021-05-24 10:45 ` Steven Price
2021-05-24 10:45 ` [PATCH v13 3/8] arm64: mte: Sync tags for pages where PTE is untagged Steven Price
2021-05-24 10:45 ` Steven Price
2021-05-24 10:45 ` Steven Price
2021-05-24 10:45 ` Steven Price
2021-06-03 14:20 ` Catalin Marinas
2021-06-03 14:20 ` Catalin Marinas
2021-06-03 14:20 ` Catalin Marinas
2021-06-03 14:20 ` Catalin Marinas
2021-05-24 10:45 ` [PATCH v13 4/8] KVM: arm64: Introduce MTE VM feature Steven Price
2021-05-24 10:45 ` Steven Price
2021-05-24 10:45 ` Steven Price
2021-05-24 10:45 ` Steven Price
2021-06-03 16:00 ` Catalin Marinas
2021-06-03 16:00 ` Catalin Marinas
2021-06-03 16:00 ` Catalin Marinas
2021-06-03 16:00 ` Catalin Marinas
2021-06-04 9:01 ` Catalin Marinas
2021-06-04 9:01 ` Catalin Marinas
2021-06-04 9:01 ` Catalin Marinas
2021-06-04 9:01 ` Catalin Marinas
2021-06-04 10:42 ` Steven Price
2021-06-04 10:42 ` Steven Price
2021-06-04 10:42 ` Steven Price
2021-06-04 10:42 ` Steven Price
2021-06-04 11:36 ` Catalin Marinas
2021-06-04 11:36 ` Catalin Marinas
2021-06-04 11:36 ` Catalin Marinas
2021-06-04 11:36 ` Catalin Marinas
2021-06-04 12:51 ` Steven Price
2021-06-04 12:51 ` Steven Price
2021-06-04 12:51 ` Steven Price
2021-06-04 12:51 ` Steven Price
2021-06-04 14:05 ` Catalin Marinas
2021-06-04 14:05 ` Catalin Marinas
2021-06-04 14:05 ` Catalin Marinas
2021-06-04 14:05 ` Catalin Marinas
2021-05-24 10:45 ` [PATCH v13 5/8] KVM: arm64: Save/restore MTE registers Steven Price
2021-05-24 10:45 ` Steven Price
2021-05-24 10:45 ` Steven Price
2021-05-24 10:45 ` Steven Price
2021-06-03 16:48 ` Catalin Marinas
2021-06-03 16:48 ` Catalin Marinas
2021-06-03 16:48 ` Catalin Marinas
2021-06-03 16:48 ` Catalin Marinas
2021-05-24 10:45 ` [PATCH v13 6/8] KVM: arm64: Expose KVM_ARM_CAP_MTE Steven Price
2021-05-24 10:45 ` Steven Price
2021-05-24 10:45 ` Steven Price
2021-05-24 10:45 ` Steven Price
2021-06-03 16:58 ` Catalin Marinas
2021-06-03 16:58 ` Catalin Marinas
2021-06-03 16:58 ` Catalin Marinas
2021-06-03 16:58 ` Catalin Marinas
2021-05-24 10:45 ` [PATCH v13 7/8] KVM: arm64: ioctl to fetch/store tags in a guest Steven Price
2021-05-24 10:45 ` Steven Price
2021-05-24 10:45 ` Steven Price
2021-05-24 10:45 ` Steven Price
2021-06-03 17:13 ` Catalin Marinas [this message]
2021-06-03 17:13 ` Catalin Marinas
2021-06-03 17:13 ` Catalin Marinas
2021-06-03 17:13 ` Catalin Marinas
2021-06-04 11:15 ` Steven Price
2021-06-04 11:15 ` Steven Price
2021-06-04 11:15 ` Steven Price
2021-06-04 11:15 ` Steven Price
2021-06-04 11:42 ` Catalin Marinas
2021-06-04 11:42 ` Catalin Marinas
2021-06-04 11:42 ` Catalin Marinas
2021-06-04 11:42 ` Catalin Marinas
2021-06-04 13:09 ` Steven Price
2021-06-04 13:09 ` Steven Price
2021-06-04 13:09 ` Steven Price
2021-06-04 13:09 ` Steven Price
2021-06-04 15:34 ` Catalin Marinas
2021-06-04 15:34 ` Catalin Marinas
2021-06-04 15:34 ` Catalin Marinas
2021-06-04 15:34 ` Catalin Marinas
2021-05-24 10:45 ` [PATCH v13 8/8] KVM: arm64: Document MTE capability and ioctl Steven Price
2021-05-24 10:45 ` Steven Price
2021-05-24 10:45 ` Steven Price
2021-05-24 10:45 ` Steven Price
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