From 85bd0ba1ff9875798fad94218b627ea9f768f3c3 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Sun, 21 Jan 2018 16:42:56 +0000 Subject: arm/arm64: KVM: Add PSCI version selection API Although we've implemented PSCI 0.1, 0.2 and 1.0, we expose either 0.1 or 1.0 to a guest, defaulting to the latest version of the PSCI implementation that is compatible with the requested version. This is no different from doing a firmware upgrade on KVM. But in order to give a chance to hypothetical badly implemented guests that would have a fit by discovering something other than PSCI 0.2, let's provide a new API that allows userspace to pick one particular version of the API. This is implemented as a new class of "firmware" registers, where we expose the PSCI version. This allows the PSCI version to be save/restored as part of a guest migration, and also set to any supported version if the guest requires it. Cc: stable@vger.kernel.org #4.16 Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier --- arch/arm/include/asm/kvm_host.h | 3 +++ arch/arm/include/uapi/asm/kvm.h | 6 ++++++ 2 files changed, 9 insertions(+) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index c6a749568dd6..c7c28c885a19 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -77,6 +77,9 @@ struct kvm_arch { /* Interrupt controller */ struct vgic_dist vgic; int max_vcpus; + + /* Mandated version of PSCI */ + u32 psci_version; }; #define KVM_NR_MEM_OBJS 40 diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h index 2ba95d6fe852..caae4843cb70 100644 --- a/arch/arm/include/uapi/asm/kvm.h +++ b/arch/arm/include/uapi/asm/kvm.h @@ -195,6 +195,12 @@ struct kvm_arch_memory_slot { #define KVM_REG_ARM_VFP_FPINST 0x1009 #define KVM_REG_ARM_VFP_FPINST2 0x100A +/* KVM-as-firmware specific pseudo-registers */ +#define KVM_REG_ARM_FW (0x0014 << KVM_REG_ARM_COPROC_SHIFT) +#define KVM_REG_ARM_FW_REG(r) (KVM_REG_ARM | KVM_REG_SIZE_U64 | \ + KVM_REG_ARM_FW | ((r) & 0xffff)) +#define KVM_REG_ARM_PSCI_VERSION KVM_REG_ARM_FW_REG(0) + /* Device Control API: ARM VGIC */ #define KVM_DEV_ARM_VGIC_GRP_ADDR 0 #define KVM_DEV_ARM_VGIC_GRP_DIST_REGS 1 -- cgit v1.2.3