linux/Documentation/virt/kvm/arm, branch master

KVM: arm64: Add some initial documentation for pKVM

2026-03-30T15:58:09Z

Add some initial documentation for pKVM to help people understand what is supported, the limitations of protected VMs when compared to non-protected VMs and also what is left to do. Reviewed-by: Fuad Tabba Tested-by: Fuad Tabba Tested-by: Mostafa Saleh Signed-off-by: Will Deacon Link: https://patch.msgid.link/20260330144841.26181-33-will@kernel.org Signed-off-by: Marc Zyngier

KVM: arm64: Introduce KVM_REG_ARM_VENDOR_HYP_BMAP_2

2025-02-26T21:30:36Z

The vendor_hyp_bmap bitmap holds the information about the Vendor Hyp services available to the user space and can be get/set using {G, S}ET_ONE_REG interfaces. This is done using the pseudo-firmware bitmap register KVM_REG_ARM_VENDOR_HYP_BMAP. At present, this bitmap is a 64 bit one and since the function numbers for newly added DISCOVER_IPML_* hypercalls are 64-65, introduce another pseudo-firmware bitmap register KVM_REG_ARM_VENDOR_HYP_BMAP_2. Reviewed-by: Sebastian Ott Signed-off-by: Shameer Kolothum Link: https://lore.kernel.org/r/20250221140229.12588-4-shameerali.kolothum.thodi@huawei.com Signed-off-by: Oliver Upton

KVM: arm64: Specify hypercall ABI for retrieving target implementations

2025-02-26T21:30:18Z

If the Guest requires migration to multiple targets, these hypercalls will provide a way to retrieve the target CPU implementations from the user space VMM. Subsequent patch will use this to enable the associated errata. Suggested-by: Oliver Upton Suggested-by: Marc Zyngier Reviewed-by: Cornelia Huck Reviewed-by: Sebastian Ott Signed-off-by: Shameer Kolothum Link: https://lore.kernel.org/r/20250221140229.12588-3-shameerali.kolothum.thodi@huawei.com Signed-off-by: Oliver Upton

drivers/virt: pkvm: Intercept ioremap using pKVM MMIO_GUARD hypercall

2024-08-30T15:30:41Z

Hook up pKVM's MMIO_GUARD hypercall so that ioremap() and friends will register the target physical address as MMIO with the hypervisor, allowing guest exits to that page to be emulated by the host with full syndrome information. Acked-by: Marc Zyngier Link: https://lore.kernel.org/r/20240830130150.8568-7-will@kernel.org Signed-off-by: Will Deacon

drivers/virt: pkvm: Hook up mem_encrypt API using pKVM hypercalls

2024-08-30T15:30:41Z

If we detect the presence of pKVM's SHARE and UNSHARE hypercalls, then register a backend implementation of the mem_encrypt API so that things like DMA buffers can be shared appropriately with the host. Acked-by: Marc Zyngier Link: https://lore.kernel.org/r/20240830130150.8568-5-will@kernel.org Signed-off-by: Will Deacon

drivers/virt: pkvm: Add initial support for running as a protected guest

2024-08-30T15:30:41Z

Implement a pKVM protected guest driver to probe the presence of pKVM and determine the memory protection granule using the HYP_MEMINFO hypercall. Acked-by: Marc Zyngier Link: https://lore.kernel.org/r/20240830130150.8568-3-will@kernel.org Signed-off-by: Will Deacon

KVM: arm64: Document the KVM/arm64-specific calls in hypercalls.rst

2024-05-01T15:48:14Z

KVM/arm64 makes use of the SMCCC "Vendor Specific Hypervisor Service Call Range" to expose KVM-specific hypercalls to guests in a discoverable and extensible fashion. Document the existence of this interface and the discovery hypercall. Signed-off-by: Will Deacon Signed-off-by: Fuad Tabba Acked-by: Oliver Upton Link: https://lore.kernel.org/r/20240423150538.2103045-28-tabba@google.com Signed-off-by: Marc Zyngier

KVM: arm64: Rename firmware pseudo-register documentation file

2024-05-01T15:48:14Z

In preparation for describing the guest view of KVM/arm64 hypercalls in hypercalls.rst, move the existing contents of the file concerning the firmware pseudo-registers elsewhere. Cc: Raghavendra Rao Ananta Signed-off-by: Will Deacon Signed-off-by: Fuad Tabba Acked-by: Oliver Upton Link: https://lore.kernel.org/r/20240423150538.2103045-27-tabba@google.com Signed-off-by: Marc Zyngier

KVM: arm64: Reformat/beautify PTP hypercall documentation

2024-05-01T15:48:14Z

The PTP hypercall documentation doesn't produce the best-looking table when formatting in HTML as all of the return value definitions end up on the same line. Reformat the PTP hypercall documentation to follow the formatting used by hypercalls.rst. Signed-off-by: Will Deacon Signed-off-by: Fuad Tabba Acked-by: Oliver Upton Link: https://lore.kernel.org/r/20240423150538.2103045-26-tabba@google.com Signed-off-by: Marc Zyngier

KVM: arm64: Document vCPU feature selection UAPIs

2023-10-04T17:11:51Z

KVM/arm64 has a couple schemes for handling vCPU feature selection now, which is a lot to put on userspace. Add some documentation about how these interact and provide some recommendations for how to use the writable ID register scheme. Reviewed-by: Marc Zyngier Link: https://lore.kernel.org/r/20231003230408.3405722-11-oliver.upton@linux.dev Signed-off-by: Oliver Upton