arm64: KVM: vgic-v2: Add GICV access from HYP
authorMarc Zyngier <marc.zyngier@arm.com>
Tue, 6 Sep 2016 08:28:46 +0000 (09:28 +0100)
committerChristoffer Dall <christoffer.dall@linaro.org>
Thu, 8 Sep 2016 10:53:00 +0000 (12:53 +0200)
Now that we have the necessary infrastructure to handle MMIO accesses
in HYP, perform the GICV access on behalf of the guest. This requires
checking that the access is strictly 32bit, properly aligned, and
falls within the expected range.

When all condition are satisfied, we perform the access and tell
the rest of the HYP code that the instruction has been correctly
emulated.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
include/kvm/arm_vgic.h
virt/kvm/arm/hyp/vgic-v2-sr.c

index 8eb1501fc1d0eac85096591d2088ae2192c8bb0c..bb46c03eb3c730e7ece3ab447ad6e44dbf756478 100644 (file)
@@ -50,6 +50,9 @@ struct vgic_global {
        /* Physical address of vgic virtual cpu interface */
        phys_addr_t             vcpu_base;
 
+       /* GICV mapping */
+       void __iomem            *vcpu_base_va;
+
        /* virtual control interface mapping */
        void __iomem            *vctrl_base;
 
index 3e2a62e27ebac5672ed5a79f199110d1723171a0..a052f2056cc0fce07cae3ca8a65a1429a0d23e92 100644 (file)
@@ -19,6 +19,7 @@
 #include <linux/irqchip/arm-gic.h>
 #include <linux/kvm_host.h>
 
+#include <asm/kvm_emulate.h>
 #include <asm/kvm_hyp.h>
 
 static void __hyp_text save_maint_int_state(struct kvm_vcpu *vcpu,
@@ -171,6 +172,44 @@ void __hyp_text __vgic_v2_restore_state(struct kvm_vcpu *vcpu)
 #ifdef CONFIG_ARM64
 bool __hyp_text __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu)
 {
+       struct kvm *kvm = kern_hyp_va(vcpu->kvm);
+       struct vgic_dist *vgic = &kvm->arch.vgic;
+       phys_addr_t fault_ipa;
+       void __iomem *addr;
+       int rd;
+
+       /* Build the full address */
+       fault_ipa  = kvm_vcpu_get_fault_ipa(vcpu);
+       fault_ipa |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0);
+
+       /* If not for GICV, move on */
+       if (fault_ipa <  vgic->vgic_cpu_base ||
+           fault_ipa >= (vgic->vgic_cpu_base + KVM_VGIC_V2_CPU_SIZE))
                return false;
+
+       /* Reject anything but a 32bit access */
+       if (kvm_vcpu_dabt_get_as(vcpu) != sizeof(u32))
+               return false;
+
+       /* Not aligned? Don't bother */
+       if (fault_ipa & 3)
+               return false;
+
+       rd = kvm_vcpu_dabt_get_rd(vcpu);
+       addr  = kern_hyp_va((kern_hyp_va(&kvm_vgic_global_state))->vcpu_base_va);
+       addr += fault_ipa - vgic->vgic_cpu_base;
+
+       if (kvm_vcpu_dabt_iswrite(vcpu)) {
+               u32 data = vcpu_data_guest_to_host(vcpu,
+                                                  vcpu_get_reg(vcpu, rd),
+                                                  sizeof(u32));
+               writel_relaxed(data, addr);
+       } else {
+               u32 data = readl_relaxed(addr);
+               vcpu_set_reg(vcpu, rd, vcpu_data_host_to_guest(vcpu, data,
+                                                              sizeof(u32)));
+       }
+
+       return true;
 }
 #endif