[RFC 27/55] KVM: arm/arm64: Emulate GICH interface on GICv2

Jintack Lim
2017-01-09T06:24:23Z

Emulate GICH interface accesses from the guest hypervisor.

Signed-off-by: Jintack Lim <jintack@cs.columbia.edu>
Signed-off-by: Shih-Wei Li <shihwei@cs.columbia.edu>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
---
arch/arm64/kvm/Makefile | 1 +
virt/kvm/arm/vgic/vgic-v2-nested.c | 207 +++++++++++++++++++++++++++++++++++++
2 files changed, 208 insertions(+)
create mode 100644 virt/kvm/arm/vgic/vgic-v2-nested.c

diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index 9c35e9a..8573faf 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -37,3 +37,4 @@ kvm-$(CONFIG_KVM_ARM_PMU) += $(KVM)/arm/pmu.o

kvm-$(CONFIG_KVM_ARM_NESTED_HYP) += handle_exit_nested.o
kvm-$(CONFIG_KVM_ARM_NESTED_HYP) += emulate-nested.o
+kvm-$(CONFIG_KVM_ARM_NESTED_HYP) += $(KVM)/arm/vgic/vgic-v2-nested.o
diff --git a/virt/kvm/arm/vgic/vgic-v2-nested.c b/virt/kvm/arm/vgic/vgic-v2-nested.c
new file mode 100644
index 0000000..b13128e
--- /dev/null
+++ b/virt/kvm/arm/vgic/vgic-v2-nested.c
@@ -0,0 +1,207 @@
+#include <linux/cpu.h>
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+
+#include <linux/irqchip/arm-gic.h>
+
+#include <asm/kvm_emulate.h>
+#include <asm/kvm_arm.h>
+#include <asm/kvm_mmu.h>
+#include <kvm/arm_vgic.h>
+
+#include "vgic.h"
+#include "vgic-mmio.h"
+
+static inline struct vgic_v2_cpu_if *vcpu_nested_if(struct kvm_vcpu *vcpu)
+{
+ return &vcpu->arch.vgic_cpu.nested_vgic_v2;
+}
+
+static inline struct vgic_v2_cpu_if *vcpu_shadow_if(struct kvm_vcpu *vcpu)
+{
+ return &vcpu->arch.vgic_cpu.shadow_vgic_v2;
+}
+
+static unsigned long vgic_mmio_read_v2_vtr(struct kvm_vcpu *vcpu,
+ gpa_t addr, unsigned int len)
+{
+ u32 reg;
+
+ reg = kvm_vgic_global_state.nr_lr - 1;
+ reg |= 0b100 << 26;
+ reg |= 0b100 << 29;
+
+ return reg;
+}
+
+static inline bool lr_triggers_eoi(u32 lr)
+{
+ return !(lr & (GICH_LR_STATE | GICH_LR_HW)) && (lr & GICH_LR_EOI);
+}
+
+static unsigned long get_eisr(struct kvm_vcpu *vcpu, bool upper_reg)
+{
+ struct vgic_v2_cpu_if *cpu_if = vcpu_nested_if(vcpu);
+ int max_lr = upper_reg ? 64 : 32;
+ int min_lr = upper_reg ? 32 : 0;
+ int nr_lr = min(kvm_vgic_global_state.nr_lr, max_lr);
+ int i;
+ u32 reg = 0;
+
+ for (i = min_lr; i < nr_lr; i++) {
+ if (lr_triggers_eoi(cpu_if->vgic_lr[i]))
+ reg |= BIT(i - min_lr);
+ }
+
+ return reg;
+}
+
+static unsigned long vgic_mmio_read_v2_eisr0(struct kvm_vcpu *vcpu,
+ gpa_t addr, unsigned int len)
+{
+ return get_eisr(vcpu, false);
+}
+
+static unsigned long vgic_mmio_read_v2_eisr1(struct kvm_vcpu *vcpu,
+ gpa_t addr, unsigned int len)
+{
+ return get_eisr(vcpu, true);
+}
+
+static u32 get_elrsr(struct kvm_vcpu *vcpu, bool upper_reg)
+{
+ struct vgic_v2_cpu_if *cpu_if = vcpu_nested_if(vcpu);
+ int max_lr = upper_reg ? 64 : 32;
+ int min_lr = upper_reg ? 32 : 0;
+ int nr_lr = min(kvm_vgic_global_state.nr_lr, max_lr);
+ u32 reg = 0;
+ int i;
+
+ for (i = min_lr; i < nr_lr; i++) {
+ if (!(cpu_if->vgic_lr[i] & GICH_LR_STATE))
+ reg |= BIT(i - min_lr);
+ }
+
+ return reg;
+}
+
+static unsigned long vgic_mmio_read_v2_elrsr0(struct kvm_vcpu *vcpu,
+ gpa_t addr, unsigned int len)
+{
+ return get_elrsr(vcpu, false);
+}
+
+static unsigned long vgic_mmio_read_v2_elrsr1(struct kvm_vcpu *vcpu,
+ gpa_t addr, unsigned int len)
+{
+ return get_elrsr(vcpu, true);
+}
+
+static unsigned long vgic_mmio_read_v2_misr(struct kvm_vcpu *vcpu,
+ gpa_t addr, unsigned int len)
+{
+ struct vgic_v2_cpu_if *cpu_if = vcpu_nested_if(vcpu);
+ int nr_lr = kvm_vgic_global_state.nr_lr;
+ u32 reg = 0;
+
+ if (vgic_mmio_read_v2_eisr0(vcpu, addr, len) ||
+ vgic_mmio_read_v2_eisr1(vcpu, addr, len))
+ reg |= GICH_MISR_EOI;
+
+ if (cpu_if->vgic_hcr & GICH_HCR_UIE) {
+ u32 elrsr0 = vgic_mmio_read_v2_elrsr0(vcpu, addr, len);
+ u32 elrsr1 = vgic_mmio_read_v2_elrsr1(vcpu, addr, len);
+ int used_lrs;
+
+ used_lrs = nr_lr - (hweight32(elrsr0) + hweight32(elrsr1));
+ if (used_lrs <= 1)
+ reg |= GICH_MISR_U;
+ }
+
+ /* TODO: Support remaining bits in this register */
+ return reg;
+}
+
+static unsigned long vgic_mmio_read_v2_gich(struct kvm_vcpu *vcpu,
+ gpa_t addr, unsigned int len)
+{
+ struct vgic_v2_cpu_if *cpu_if = vcpu_nested_if(vcpu);
+ u32 value;
+
+ switch (addr & 0xfff) {
+ case GICH_HCR:
+ value = cpu_if->vgic_hcr;
+ break;
+ case GICH_VMCR:
+ value = cpu_if->vgic_vmcr;
+ break;
+ case GICH_APR:
+ value = cpu_if->vgic_apr;
+ break;
+ case GICH_LR0 ... (GICH_LR0 + 4 * (VGIC_V2_MAX_LRS - 1)):
+ value = cpu_if->vgic_lr[(addr & 0xff) >> 2];
+ break;
+ default:
+ return 0;
+ }
+
+ return value;
+}
+
+static void vgic_mmio_write_v2_gich(struct kvm_vcpu *vcpu,
+ gpa_t addr, unsigned int len,
+ unsigned long val)
+{
+ struct vgic_v2_cpu_if *cpu_if = vcpu_nested_if(vcpu);
+
+ switch (addr & 0xfff) {
+ case GICH_HCR:
+ cpu_if->vgic_hcr = val;
+ break;
+ case GICH_VMCR:
+ cpu_if->vgic_vmcr = val;
+ break;
+ case GICH_APR:
+ cpu_if->vgic_apr = val;
+ break;
+ case GICH_LR0 ... (GICH_LR0 + 4 * (VGIC_V2_MAX_LRS - 1)):
+ cpu_if->vgic_lr[(addr & 0xff) >> 2] = val;
+ break;
+ }
+}
+
+static const struct vgic_register_region vgic_v2_gich_registers[] = {
+ REGISTER_DESC_WITH_LENGTH(GICH_HCR,
+ vgic_mmio_read_v2_gich, vgic_mmio_write_v2_gich, 4,
+ VGIC_ACCESS_32bit),
+ REGISTER_DESC_WITH_LENGTH(GICH_VTR,
+ vgic_mmio_read_v2_vtr, vgic_mmio_write_wi, 4,
+ VGIC_ACCESS_32bit),
+ REGISTER_DESC_WITH_LENGTH(GICH_VMCR,
+ vgic_mmio_read_v2_gich, vgic_mmio_write_v2_gich, 4,
+ VGIC_ACCESS_32bit),
+ REGISTER_DESC_WITH_LENGTH(GICH_MISR,
+ vgic_mmio_read_v2_misr, vgic_mmio_write_wi, 4,
+ VGIC_ACCESS_32bit),
+ REGISTER_DESC_WITH_LENGTH(GICH_EISR0,
+ vgic_mmio_read_v2_eisr0, vgic_mmio_write_wi, 4,
+ VGIC_ACCESS_32bit),
+ REGISTER_DESC_WITH_LENGTH(GICH_EISR1,
+ vgic_mmio_read_v2_eisr1, vgic_mmio_write_wi, 4,
+ VGIC_ACCESS_32bit),
+ REGISTER_DESC_WITH_LENGTH(GICH_ELRSR0,
+ vgic_mmio_read_v2_elrsr0, vgic_mmio_write_wi, 4,
+ VGIC_ACCESS_32bit),
+ REGISTER_DESC_WITH_LENGTH(GICH_ELRSR1,
+ vgic_mmio_read_v2_elrsr1, vgic_mmio_write_wi, 4,
+ VGIC_ACCESS_32bit),
+ REGISTER_DESC_WITH_LENGTH(GICH_APR,
+ vgic_mmio_read_v2_gich, vgic_mmio_write_v2_gich, 4,
+ VGIC_ACCESS_32bit),
+ REGISTER_DESC_WITH_LENGTH(GICH_LR0,
+ vgic_mmio_read_v2_gich, vgic_mmio_write_v2_gich,
+ 4 * VGIC_V2_MAX_LRS, VGIC_ACCESS_32bit),
+};
--
1.9.1