From: Julien Thierry <julien.thierry@arm.com>
To: Dave Martin <Dave.Martin@arm.com>, kvmarm@lists.cs.columbia.edu
Cc: Okamoto Takayuki <tokamoto@jp.fujitsu.com>,
Christoffer Dall <cdall@kernel.org>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Marc Zyngier <marc.zyngier@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Zhang Lei <zhang.lei@jp.fujitsu.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v5 17/26] KVM: arm64: Reject ioctl access to FPSIMD V-regs on SVE vcpus
Date: Thu, 21 Feb 2019 12:06:23 +0000 [thread overview]
Message-ID: <696ae744-c016-9cc2-d393-fd321d341df4@arm.com> (raw)
In-Reply-To: <1550519559-15915-18-git-send-email-Dave.Martin@arm.com>
On 18/02/2019 19:52, Dave Martin wrote:
> In order to avoid the pointless complexity of maintaining two ioctl
> register access views of the same data, this patch blocks ioctl
> access to the FPSIMD V-registers on vcpus that support SVE.
>
> This will make it more straightforward to add SVE register access
> support.
>
> Since SVE is an opt-in feature for userspace, this will not affect
> existing users.
>
> Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
> ---
> arch/arm64/kvm/guest.c | 38 +++++++++++++++++++++++++++-----------
> 1 file changed, 27 insertions(+), 11 deletions(-)
>
> diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
> index f83fe22..f491456 100644
> --- a/arch/arm64/kvm/guest.c
> +++ b/arch/arm64/kvm/guest.c
> @@ -95,7 +95,14 @@ static int core_reg_size_from_offset(u64 off)
> return -EINVAL;
> }
>
> -static int validate_core_offset(const struct kvm_one_reg *reg)
> +static bool core_reg_offset_is_vreg(u64 off)
> +{
> + return off >= KVM_REG_ARM_CORE_REG(fp_regs.vregs) &&
> + off < KVM_REG_ARM_CORE_REG(fp_regs.fpsr);
> +}
> +
> +static int validate_core_offset(const struct kvm_vcpu *vcpu,
> + const struct kvm_one_reg *reg)
> {
> u64 off = core_reg_offset_from_id(reg->id);
> int size = core_reg_size_from_offset(off);
> @@ -103,10 +110,18 @@ static int validate_core_offset(const struct kvm_one_reg *reg)
> if (size < 0)
> return -EINVAL;
>
> - if (KVM_REG_SIZE(reg->id) == size)
> - return 0;
> + if (KVM_REG_SIZE(reg->id) != size)
> + return -EINVAL;
>
> - return -EINVAL;
> + /*
> + * The KVM_REG_ARM64_SVE regs must be used instead of
> + * KVM_REG_ARM_CORE for accessing the FPSIMD V-registers on
> + * SVE-enabled vcpus:
> + */
> + if (vcpu_has_sve(vcpu) && core_reg_offset_is_vreg(off))
> + return -EINVAL;
> +
> + return 0;
> }
>
> static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
> @@ -128,7 +143,7 @@ static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
> (off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
> return -ENOENT;
>
> - if (validate_core_offset(reg))
> + if (validate_core_offset(vcpu, reg))
> return -EINVAL;
>
> if (copy_to_user(uaddr, ((u32 *)regs) + off, KVM_REG_SIZE(reg->id)))
> @@ -153,7 +168,7 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
> (off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
> return -ENOENT;
>
> - if (validate_core_offset(reg))
> + if (validate_core_offset(vcpu, reg))
> return -EINVAL;
>
> if (KVM_REG_SIZE(reg->id) > sizeof(tmp))
> @@ -206,7 +221,8 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
> return -EINVAL;
> }
>
> -static int copy_core_reg_indices(u64 __user **uind)
> +static int copy_core_reg_indices(const struct kvm_vcpu *vcpu,
> + u64 __user **uind)
> {
> unsigned int i;
> int n = 0;
> @@ -248,9 +264,9 @@ static int copy_core_reg_indices(u64 __user **uind)
> return n;
> }
>
> -static unsigned long num_core_regs(void)
> +static unsigned long num_core_regs(const struct kvm_vcpu *vcpu)
> {
> - return copy_core_reg_indices(NULL);
> + return copy_core_reg_indices(vcpu, NULL);
> }
>
> /**
> @@ -315,7 +331,7 @@ unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu)
> {
> unsigned long res = 0;
>
> - res += num_core_regs();
> + res += num_core_regs(vcpu);
> res += kvm_arm_num_sys_reg_descs(vcpu);
> res += kvm_arm_get_fw_num_regs(vcpu);
> res += NUM_TIMER_REGS;
> @@ -332,7 +348,7 @@ int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
> {
> int ret;
>
> - ret = copy_core_reg_indices(&uindices);
> + ret = copy_core_reg_indices(vcpu, &uindices);
> if (ret < 0)
> return ret;
>
>
--
Julien Thierry
_______________________________________________
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:[~2019-02-21 12:06 UTC|newest]
Thread overview: 96+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-18 19:52 [PATCH v5 00/26] KVM: arm64: SVE guest support Dave Martin
2019-02-18 19:52 ` [PATCH v5 01/26] KVM: Documentation: Document arm64 core registers in detail Dave Martin
2019-02-21 11:48 ` Julien Grall
2019-02-26 12:05 ` Dave Martin
2019-02-21 11:57 ` Peter Maydell
2019-02-18 19:52 ` [PATCH v5 02/26] arm64: fpsimd: Always set TIF_FOREIGN_FPSTATE on task state flush Dave Martin
2019-02-21 12:39 ` Julien Grall
2019-02-26 12:06 ` Dave Martin
2019-02-26 12:35 ` Julien Grall
2019-02-18 19:52 ` [PATCH v5 03/26] KVM: arm64: Delete orphaned declaration for __fpsimd_enabled() Dave Martin
2019-02-18 19:52 ` [PATCH v5 04/26] KVM: arm64: Refactor kvm_arm_num_regs() for easier maintenance Dave Martin
2019-02-18 19:52 ` [PATCH v5 05/26] KVM: arm64: Add missing #include of <linux/bitmap.h> to kvm_host.h Dave Martin
2019-02-20 15:23 ` Mark Rutland
2019-02-26 12:06 ` Dave Martin
2019-02-26 12:31 ` Mark Rutland
2019-02-26 12:33 ` Dave Martin
2019-02-26 12:40 ` Mark Rutland
2019-02-18 19:52 ` [PATCH v5 06/26] arm64/sve: Check SVE virtualisability Dave Martin
2019-02-20 11:12 ` Julien Thierry
2019-02-26 12:06 ` Dave Martin
2019-03-01 12:39 ` Julien Thierry
2019-03-01 14:44 ` Dave Martin
2019-02-21 13:36 ` Julien Grall
2019-02-26 12:06 ` Dave Martin
2019-02-26 15:43 ` Julien Grall
2019-02-18 19:52 ` [PATCH v5 07/26] arm64/sve: Clarify role of the VQ map maintenance functions Dave Martin
2019-02-20 11:43 ` Julien Thierry
2019-02-26 12:06 ` Dave Martin
2019-02-21 13:46 ` Julien Grall
2019-02-26 12:07 ` Dave Martin
2019-02-18 19:52 ` [PATCH v5 08/26] arm64/sve: Enable SVE state tracking for non-task contexts Dave Martin
2019-02-22 15:26 ` Julien Grall
2019-02-26 12:07 ` Dave Martin
2019-02-26 15:49 ` Julien Grall
2019-02-26 15:58 ` Dave Martin
2019-02-26 15:59 ` Julien Grall
2019-02-26 16:03 ` Dave Martin
2019-02-18 19:52 ` [PATCH v5 09/26] KVM: arm64: Add a vcpu flag to control SVE visibility for the guest Dave Martin
2019-02-18 19:52 ` [PATCH v5 10/26] KVM: arm64: Propagate vcpu into read_id_reg() Dave Martin
2019-02-18 19:52 ` [PATCH v5 11/26] KVM: arm64: Extend reset_unknown() to handle mixed RES0/UNKNOWN registers Dave Martin
2019-02-20 13:33 ` Julien Thierry
2019-02-26 12:07 ` Dave Martin
2019-02-22 16:04 ` Julien Grall
2019-02-18 19:52 ` [PATCH v5 12/26] KVM: arm64: Support runtime sysreg visibility filtering Dave Martin
2019-02-20 14:33 ` Julien Thierry
2019-02-26 12:07 ` Dave Martin
2019-02-20 15:37 ` Mark Rutland
2019-02-26 12:12 ` Dave Martin
2019-02-18 19:52 ` [PATCH v5 13/26] KVM: arm64/sve: System register context switch and access support Dave Martin
2019-02-20 16:48 ` Julien Thierry
2019-02-26 16:32 ` Julien Grall
2019-02-26 17:01 ` Dave Martin
2019-02-27 12:02 ` Julien Grall
2019-02-27 13:50 ` Dave Martin
2019-02-27 14:17 ` Julien Grall
2019-02-27 14:38 ` Dave Martin
2019-02-18 19:52 ` [PATCH v5 14/26] KVM: arm64/sve: Context switch the SVE registers Dave Martin
2019-02-20 16:19 ` Mark Rutland
2019-02-26 12:13 ` Dave Martin
2019-02-20 16:46 ` Julien Thierry
2019-02-26 12:13 ` Dave Martin
2019-02-26 16:56 ` Julien Grall
2019-02-27 13:37 ` Dave Martin
2019-02-18 19:52 ` [PATCH v5 15/26] KVM: Allow 2048-bit register access via ioctl interface Dave Martin
2019-02-18 19:52 ` [PATCH v5 16/26] KVM: arm64: Add missing #include of <linux/string.h> in guest.c Dave Martin
2019-02-18 19:52 ` [PATCH v5 17/26] KVM: arm64: Reject ioctl access to FPSIMD V-regs on SVE vcpus Dave Martin
2019-02-21 12:06 ` Julien Thierry [this message]
2019-02-26 12:13 ` Dave Martin
2019-02-18 19:52 ` [PATCH v5 18/26] KVM: arm64/sve: Add SVE support to register access ioctl interface Dave Martin
2019-02-21 15:23 ` Julien Thierry
2019-02-26 12:13 ` Dave Martin
2019-03-01 13:03 ` Julien Thierry
2019-03-01 14:45 ` Dave Martin
2019-02-18 19:52 ` [PATCH v5 19/26] KVM: arm64: Enumerate SVE register indices for KVM_GET_REG_LIST Dave Martin
2019-02-21 16:28 ` Julien Thierry
2019-02-18 19:52 ` [PATCH v5 20/26] arm64/sve: In-kernel vector length availability query interface Dave Martin
2019-02-18 19:52 ` [PATCH v5 21/26] KVM: arm/arm64: Add hook to finalize the vcpu configuration Dave Martin
2019-02-18 19:52 ` [PATCH v5 22/26] KVM: arm64/sve: Add pseudo-register for the guest's vector lengths Dave Martin
2019-02-21 17:48 ` Julien Thierry
2019-02-26 12:13 ` Dave Martin
2019-03-01 13:28 ` Julien Thierry
2019-03-01 14:55 ` Dave Martin
2019-03-07 13:47 ` Marc Zyngier
2019-03-07 15:30 ` Dave Martin
2019-02-18 19:52 ` [PATCH v5 23/26] KVM: arm64/sve: Allow userspace to enable SVE for vcpus Dave Martin
2019-02-22 9:05 ` Julien Thierry
2019-02-26 12:13 ` Dave Martin
2019-02-18 19:52 ` [PATCH v5 24/26] KVM: arm64: Add a capabillity to advertise SVE support Dave Martin
2019-02-22 9:10 ` Julien Thierry
2019-02-26 12:14 ` Dave Martin
2019-02-18 19:52 ` [PATCH v5 25/26] KVM: Document errors for KVM_GET_ONE_REG and KVM_SET_ONE_REG Dave Martin
2019-02-18 19:52 ` [PATCH v5 26/26] KVM: arm64/sve: Document KVM API extensions for SVE Dave Martin
2019-02-20 15:47 ` [PATCH v5 00/26] KVM: arm64: SVE guest support Dave Martin
2019-03-03 2:40 ` Zhang, Lei
2019-03-05 9:47 ` Dave Martin
2019-03-08 7:06 ` Zhang, Lei
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