kernel/linux.git/include/linux/amd-iommu.h, branch v6.18.21

iommu/amd: KVM: SVM: Allow KVM to control need for GA log interrupts

2025-06-23T16:50:51+00:00

Add plumbing to the AMD IOMMU driver to allow KVM to control whether or not an IRTE is configured to generate GA log interrupts. KVM only needs a notification if the target vCPU is blocking, so the vCPU can be awakened. If a vCPU is preempted or exits to userspace, KVM clears is_run, but will set the vCPU back to running when userspace does KVM_RUN and/or the vCPU task is scheduled back in, i.e. KVM doesn't need a notification. Unconditionally pass "true" in all KVM paths to isolate the IOMMU changes from the KVM changes insofar as possible. Opportunistically swap the ordering of parameters for amd_iommu_update_ga() so that the match amd_iommu_activate_guest_mode(). Note, as of this writing, the AMD IOMMU manual doesn't list GALogIntr as a non-cached field, but per AMD hardware architects, it's not cached and can be safely updated without an invalidation. Link: https://lore.kernel.org/all/b29b8c22-2fd4-4b5e-b755-9198874157c7@amd.com Cc: Vasant Hegde Cc: Joao Martins Link: https://lore.kernel.org/r/20250611224604.313496-62-seanjc@google.com Signed-off-by: Sean Christopherson

iommu/amd: KVM: SVM: Set pCPU info in IRTE when setting vCPU affinity

2025-06-23T16:50:39+00:00

Now that setting vCPU affinity is guarded with ir_list_lock, i.e. now that avic_physical_id_entry can be safely accessed, set the pCPU info straight-away when setting vCPU affinity. Putting the IRTE into posted mode, and then immediately updating the IRTE a second time if the target vCPU is running is wasteful and confusing. This also fixes a flaw where a posted IRQ that arrives between putting the IRTE into guest_mode and setting the correct destination could cause the IOMMU to ring the doorbell on the wrong pCPU. Link: https://lore.kernel.org/r/20250611224604.313496-44-seanjc@google.com Signed-off-by: Sean Christopherson

iommu/amd: KVM: SVM: Infer IsRun from validity of pCPU destination

2025-06-23T16:50:37+00:00

Infer whether or not a vCPU should be marked running from the validity of the pCPU on which it is running. amd_iommu_update_ga() already skips the IRTE update if the pCPU is invalid, i.e. passing %true for is_run with an invalid pCPU would be a blatant and egregrious KVM bug. Tested-by: Sairaj Kodilkar Link: https://lore.kernel.org/r/20250611224604.313496-42-seanjc@google.com Signed-off-by: Sean Christopherson

iommu: KVM: Split "struct vcpu_data" into separate AMD vs. Intel structs

2025-06-23T16:50:31+00:00

Split the vcpu_data structure that serves as a handoff from KVM to IOMMU drivers into vendor specific structures. Overloading a single structure makes the code hard to read and maintain, is *very* misleading as it suggests that mixing vendors is actually supported, and bastardizing Intel's posted interrupt descriptor address when AMD's IOMMU already has its own structure is quite unnecessary. Tested-by: Sairaj Kodilkar Link: https://lore.kernel.org/r/20250611224604.313496-33-seanjc@google.com Signed-off-by: Sean Christopherson

iommu/amd: KVM: SVM: Use pi_desc_addr to derive ga_root_ptr

2025-06-23T16:50:24+00:00

Use vcpu_data.pi_desc_addr instead of amd_iommu_pi_data.base to get the GA root pointer. KVM is the only source of amd_iommu_pi_data.base, and KVM's one and only path for writing amd_iommu_pi_data.base computes the exact same value for vcpu_data.pi_desc_addr and amd_iommu_pi_data.base, and fills amd_iommu_pi_data.base if and only if vcpu_data.pi_desc_addr is valid, i.e. amd_iommu_pi_data.base is fully redundant. Cc: Maxim Levitsky Reviewed-by: Joao Martins Reviewed-by: Vasant Hegde Tested-by: Sairaj Kodilkar Link: https://lore.kernel.org/r/20250611224604.313496-23-seanjc@google.com Signed-off-by: Sean Christopherson

iommu/amd: KVM: SVM: Delete now-unused cached/previous GA tag fields

2025-06-20T20:52:55+00:00

Delete the amd_ir_data.prev_ga_tag field now that all usage is superfluous. Reviewed-by: Vasant Hegde Tested-by: Sairaj Kodilkar Link: https://lore.kernel.org/r/20250611224604.313496-8-seanjc@google.com Signed-off-by: Sean Christopherson

iommu/amd: remove return value of amd_iommu_detect

2025-01-06T11:42:00+00:00

The return value of amd_iommu_detect is not used, so remove it and is consistent with other iommu detect functions. Signed-off-by: Gao Shiyuan Reviewed-by: Vasant Hegde Link: https://lore.kernel.org/r/20250103165808.80939-1-gaoshiyuan@baidu.com Signed-off-by: Joerg Roedel

iommu/amd: Clean up RMP entries for IOMMU pages during SNP shutdown

2024-01-29T19:34:18+00:00

Add a new IOMMU API interface amd_iommu_snp_disable() to transition IOMMU pages to Hypervisor state from Reclaim state after SNP_SHUTDOWN_EX command. Invoke this API from the CCP driver after SNP_SHUTDOWN_EX command. Signed-off-by: Ashish Kalra Signed-off-by: Michael Roth Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20240126041126.1927228-20-michael.roth@amd.com

iommu/amd: Don't rely on external callers to enable IOMMU SNP support

2024-01-29T16:19:28+00:00

Currently, the expectation is that the kernel will call amd_iommu_snp_enable() to perform various checks and set the amd_iommu_snp_en flag that the IOMMU uses to adjust its setup routines to account for additional requirements on hosts where SNP is enabled. This is somewhat fragile as it relies on this call being done prior to IOMMU setup. It is more robust to just do this automatically as part of IOMMU initialization, so rework the code accordingly. There is still a need to export information about whether or not the IOMMU is configured in a manner compatible with SNP, so relocate the existing amd_iommu_snp_en flag so it can be used to convey that information in place of the return code that was previously provided by calls to amd_iommu_snp_enable(). While here, also adjust the kernel messages related to IOMMU SNP enablement for consistency/grammar/clarity. Suggested-by: Borislav Petkov (AMD) Signed-off-by: Ashish Kalra Co-developed-by: Michael Roth Signed-off-by: Michael Roth Signed-off-by: Borislav Petkov (AMD) Acked-by: Joerg Roedel Link: https://lore.kernel.org/r/20240126041126.1927228-4-michael.roth@amd.com

iommu/amd: Remove amd_iommu_device_info()

2023-10-06T14:01:54+00:00

No one is using this function. Hence remove it. Also move PCI device feature detection flags to amd_iommu_types.h as its only used inside AMD IOMMU driver. Signed-off-by: Vasant Hegde Reviewed-by: Jason Gunthorpe Reviewed-by: Jerry Snitselaar Tested-by: Alex Deucher Link: https://lore.kernel.org/r/20231006095706.5694-4-vasant.hegde@amd.com Signed-off-by: Joerg Roedel