kernel.git/arch/arm64/include/asm/kvm_nested.h, branch linux-6.7.y

KVM: arm64: Get rid of vCPU-scoped feature bitmap

2023-09-21T18:13:29Z

The vCPU-scoped feature bitmap was left in place a couple of releases ago in case the change to VM-scoped vCPU features broke anyone. Nobody has complained and the interop between VM and vCPU bitmaps is pretty gross. Throw it out. Link: https://lore.kernel.org/r/20230920195036.1169791-9-oliver.upton@linux.dev Signed-off-by: Oliver Upton

KVM: arm64: nv: Add trap forwarding infrastructure

2023-08-17T09:00:27Z

A significant part of what a NV hypervisor needs to do is to decide whether a trap from a L2+ guest has to be forwarded to a L1 guest or handled locally. This is done by checking for the trap bits that the guest hypervisor has set and acting accordingly, as described by the architecture. A previous approach was to sprinkle a bunch of checks in all the system register accessors, but this is pretty error prone and doesn't help getting an overview of what is happening. Instead, implement a set of global tables that describe a trap bit, combinations of trap bits, behaviours on trap, and what bits must be evaluated on a system register trap. Although this is painful to describe, this allows to specify each and every control bit in a static manner. To make it efficient, the table is inserted in an xarray that is global to the system, and checked each time we trap a system register while running a L2 guest. Add the basic infrastructure for now, while additional patches will implement configuration registers. Signed-off-by: Marc Zyngier Reviewed-by: Jing Zhang Reviewed-by: Miguel Luis Link: https://lore.kernel.org/r/20230815183903.2735724-15-maz@kernel.org

KVM: arm64: nv: Filter out unsupported features from ID regs

2023-02-11T10:13:30Z

As there is a number of features that we either can't support, or don't want to support right away with NV, let's add some basic filtering so that we don't advertize silly things to the EL2 guest. Whilst we are at it, advertize FEAT_TTL as well as FEAT_GTG, which the NV implementation will implement. Reviewed-by: Ganapatrao Kulkarni Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20230209175820.1939006-18-maz@kernel.org Signed-off-by: Oliver Upton

KVM: arm64: nv: Introduce nested virtualization VCPU feature

2023-02-11T09:16:11Z

Introduce the feature bit and a primitive that checks if the feature is set behind a static key check based on the cpus_have_const_cap check. Checking vcpu_has_nv() on systems without nested virt enabled should have negligible overhead. We don't yet allow userspace to actually set this feature. Reviewed-by: Ganapatrao Kulkarni Reviewed-by: Russell King (Oracle) Signed-off-by: Christoffer Dall Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20230209175820.1939006-4-maz@kernel.org Signed-off-by: Oliver Upton