[PATCH v3 12/47] KVM: arm64: Force guest EL1 to use user-space's partid configuration

[Jonathan Cameron]

On Mon, 12 Jan 2026 16:58:39 +0000
Ben Horgan <ben.horgan at arm.com> wrote:

> From: James Morse <james.morse at arm.com>
> 
> While we trap the guest's attempts to read/write the MPAM control
> registers, the hardware continues to use them. Guest-EL0 uses KVM's
> user-space's configuration, as the value is left in the register, and
> guest-EL1 uses either the host kernel's configuration, or in the case of
> VHE, the UNKNOWN reset value of MPAM1_EL1.
> 
> We want to force the guest-EL1 to use KVM's user-space's MPAM
> configuration. On nVHE rely on MPAM0_EL1 and MPAM1_EL1 always being
> programmed the same and on VHE copy MPAM0_EL1 into the guest's
> MPAM1_EL1. There is no need to restore as this is out of context once TGE
> is set.
> 
> Signed-off-by: James Morse <james.morse at arm.com>
> Signed-off-by: Ben Horgan <ben.horgan at arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron at huawei.com>