KVM: arm64: vgic-v3: Add ICV_BPR1_EL1 handler

BugLink: https://bugs.launchpad.net/bugs/1673564
Add a handler for reading/writing the guest's view of the ICC_BPR1_EL1
register, which is located in the ICH_VMCR_EL2.BPR1 field.

Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
(backported from commit d70c7b31a60f2458f35c226131f2a01a7a98b6cf)
[ dannf: added _vgic_v3_write_vmcr() from 328e5664. Dropped SYS_ prefix
  on ICC_BPR1_EL1 macro, which wasn't added upstream until 0e9884fe ]
Signed-off-by: dann frazier <dann.frazier@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/virt/kvm/arm/hyp/vgic-v3-sr.c b/virt/kvm/arm/hyp/vgic-v3-sr.c
index 3fb227f428e1f0d9452b43c6629c9df5d1a7be41..d736db589bc5fa9b9b2dcf385fda982762521980 100644 (file)
--- a/virt/kvm/arm/hyp/vgic-v3-sr.c
+++ b/virt/kvm/arm/hyp/vgic-v3-sr.c
@@ -417,8 +417,64 @@ u64 __hyp_text __vgic_v3_read_vmcr(void)
        return read_gicreg(ICH_VMCR_EL2);
 }
 
+void __hyp_text __vgic_v3_write_vmcr(u32 vmcr)
+{
+       write_gicreg(vmcr, ICH_VMCR_EL2);
+}
+
 #ifdef CONFIG_ARM64
 
+static int __hyp_text __vgic_v3_bpr_min(void)
+{
+       /* See Pseudocode for VPriorityGroup */
+       return 8 - vtr_to_nr_pre_bits(read_gicreg(ICH_VTR_EL2));
+}
+
+static unsigned int __hyp_text __vgic_v3_get_bpr0(u32 vmcr)
+{
+       return (vmcr & ICH_VMCR_BPR0_MASK) >> ICH_VMCR_BPR0_SHIFT;
+}
+
+static unsigned int __hyp_text __vgic_v3_get_bpr1(u32 vmcr)
+{
+       unsigned int bpr;
+
+       if (vmcr & ICH_VMCR_CBPR_MASK) {
+               bpr = __vgic_v3_get_bpr0(vmcr);
+               if (bpr < 7)
+                       bpr++;
+       } else {
+               bpr = (vmcr & ICH_VMCR_BPR1_MASK) >> ICH_VMCR_BPR1_SHIFT;
+       }
+
+       return bpr;
+}
+
+static void __hyp_text __vgic_v3_read_bpr1(struct kvm_vcpu *vcpu, u32 vmcr, int rt)
+{
+       vcpu_set_reg(vcpu, rt, __vgic_v3_get_bpr1(vmcr));
+}
+
+static void __hyp_text __vgic_v3_write_bpr1(struct kvm_vcpu *vcpu, u32 vmcr, int rt)
+{
+       u64 val = vcpu_get_reg(vcpu, rt);
+       u8 bpr_min = __vgic_v3_bpr_min();
+
+       if (vmcr & ICH_VMCR_CBPR_MASK)
+               return;
+
+       /* Enforce BPR limiting */
+       if (val < bpr_min)
+               val = bpr_min;
+
+       val <<= ICH_VMCR_BPR1_SHIFT;
+       val &= ICH_VMCR_BPR1_MASK;
+       vmcr &= ~ICH_VMCR_BPR1_MASK;
+       vmcr |= val;
+
+       __vgic_v3_write_vmcr(vmcr);
+}
+
 int __hyp_text __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu)
 {
        int rt;
@@ -441,6 +497,12 @@ int __hyp_text __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu)
        is_read = (esr & ESR_ELx_SYS64_ISS_DIR_MASK) == ESR_ELx_SYS64_ISS_DIR_READ;
 
        switch (sysreg) {
+       case ICC_BPR1_EL1:
+               if (is_read)
+                       fn = __vgic_v3_read_bpr1;
+               else
+                       fn = __vgic_v3_write_bpr1;
+               break;
        default:
                return 0;
        }