On Tue, Aug 06, 2024 at 07:11:54PM -0700, Nicolin Chen wrote:
> When VCMDQs are assigned to a VINTF owned by a guest (HYP_OWN bit unset),
> only TLB and ATC invalidation commands are supported by the VCMDQ HW. So,
> add a new helper to scan the input cmd to make sure it is supported when
> selecting a queue, though this assumes that SMMUv3 driver will only add
> the same type of commands into an arm_smmu_cmdq_batch as it does today.
>
> Note that the guest VM shouldn't have HYP_OWN bit being set regardless of
> guest kernel driver writing it or not, i.e. the hypervisor running in the
> host OS should wire this bit to zero when trapping a write access to this
> VINTF_CONFIG register from a guest kernel.
>
> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
> ---
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 22 +++++++-----
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 3 +-
> .../iommu/arm/arm-smmu-v3/tegra241-cmdqv.c | 35 ++++++++++++++++++-
> 3 files changed, 49 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> index 18d940c65e2c..8ff8e264d5e7 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -336,12 +336,13 @@ static int arm_smmu_cmdq_build_cmd(u64 *cmd, struct arm_smmu_cmdq_ent *ent)
> return 0;
> }
>
> -static struct arm_smmu_cmdq *arm_smmu_get_cmdq(struct arm_smmu_device *smmu)
> +static struct arm_smmu_cmdq *arm_smmu_get_cmdq(struct arm_smmu_device *smmu,
> + u8 opcode)
> {
> struct arm_smmu_cmdq *cmdq = NULL;
>
> if (smmu->impl && smmu->impl->get_secondary_cmdq)
> - cmdq = smmu->impl->get_secondary_cmdq(smmu);
> + cmdq = smmu->impl->get_secondary_cmdq(smmu, opcode);
>
> return cmdq ?: &smmu->cmdq;
> }
> @@ -889,7 +890,7 @@ static int __arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu,
> }
>
> return arm_smmu_cmdq_issue_cmdlist(
> - smmu, arm_smmu_get_cmdq(smmu), cmd, 1, sync);
> + smmu, arm_smmu_get_cmdq(smmu, ent->opcode), cmd, 1, sync);
> }
>
> static int arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu,
> @@ -905,10 +906,13 @@ static int arm_smmu_cmdq_issue_cmd_with_sync(struct arm_smmu_device *smmu,
> }
>
> static void arm_smmu_cmdq_batch_init(struct arm_smmu_device *smmu,
> - struct arm_smmu_cmdq_batch *cmds)
> + struct arm_smmu_cmdq_batch *cmds,
> + u8 opcode)
> {
> + WARN_ON_ONCE(!opcode);
This seems like a fairly arbitrary warning. Remove it?
> +
> cmds->num = 0;
> - cmds->cmdq = arm_smmu_get_cmdq(smmu);
> + cmds->cmdq = arm_smmu_get_cmdq(smmu, opcode);
If we stashed the opcode here, we could actually just enforce that all
commands in the batch are the same type in arm_smmu_cmdq_batch_add().
Would that work better for you or not?
Will
