diff options
| author | Andre Przywara <andre.przywara@arm.com> | 2014-06-03 08:58:15 +0200 |
|---|---|---|
| committer | Christoffer Dall <christoffer.dall@linaro.org> | 2015-01-20 18:25:28 +0100 |
| commit | 2f5fa41a7a7f47f3109a6596b0ec96258dbf06e6 (patch) | |
| tree | 6e75ee4272712add84e6d0a1f547caaacc38a7d3 /arch/arm64/kvm | |
| parent | 3caa2d8c3b2d80f5e342fe8cec07c03c8147dcab (diff) | |
arm/arm64: KVM: make the value of ICC_SRE_EL1 a per-VM variable
ICC_SRE_EL1 is a system register allowing msr/mrs accesses to the
GIC CPU interface for EL1 (guests). Currently we force it to 0, but
for proper GICv3 support we have to allow guests to use it (depending
on their selected virtual GIC model).
So add ICC_SRE_EL1 to the list of saved/restored registers on a
world switch, but actually disallow a guest to change it by only
restoring a fixed, once-initialized value.
This value depends on the GIC model userland has chosen for a guest.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Diffstat (limited to 'arch/arm64/kvm')
| -rw-r--r-- | arch/arm64/kvm/vgic-v3-switch.S | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/arch/arm64/kvm/vgic-v3-switch.S b/arch/arm64/kvm/vgic-v3-switch.S index d16046999e06..617a012a0107 100644 --- a/arch/arm64/kvm/vgic-v3-switch.S +++ b/arch/arm64/kvm/vgic-v3-switch.S @@ -148,17 +148,18 @@ * x0: Register pointing to VCPU struct */ .macro restore_vgic_v3_state - // Disable SRE_EL1 access. Necessary, otherwise - // ICH_VMCR_EL2.VFIQEn becomes one, and FIQ happens... - msr_s ICC_SRE_EL1, xzr - isb - // Compute the address of struct vgic_cpu add x3, x0, #VCPU_VGIC_CPU // Restore all interesting registers ldr w4, [x3, #VGIC_V3_CPU_HCR] ldr w5, [x3, #VGIC_V3_CPU_VMCR] + ldr w25, [x3, #VGIC_V3_CPU_SRE] + + msr_s ICC_SRE_EL1, x25 + + // make sure SRE is valid before writing the other registers + isb msr_s ICH_HCR_EL2, x4 msr_s ICH_VMCR_EL2, x5 @@ -244,9 +245,12 @@ dsb sy // Prevent the guest from touching the GIC system registers + // if SRE isn't enabled for GICv3 emulation + cbnz x25, 1f mrs_s x5, ICC_SRE_EL2 and x5, x5, #~ICC_SRE_EL2_ENABLE msr_s ICC_SRE_EL2, x5 +1: .endm ENTRY(__save_vgic_v3_state) |