ARM: KVM: VGIC control interface world switch

Enable the VGIC control interface to be save-restored on world switch.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

2 files changed, 86 insertions, 0 deletions

diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
index c8b3272dfed1..17cea2e78d88 100644
--- a/arch/arm/kernel/asm-offsets.c
+++ b/arch/arm/kernel/asm-offsets.c
@@ -169,6 +169,18 @@ int main(void)
   DEFINE(VCPU_HxFAR,            offsetof(struct kvm_vcpu, arch.hxfar));
   DEFINE(VCPU_HPFAR,            offsetof(struct kvm_vcpu, arch.hpfar));
   DEFINE(VCPU_HYP_PC,           offsetof(struct kvm_vcpu, arch.hyp_pc));
+#ifdef CONFIG_KVM_ARM_VGIC
+  DEFINE(VCPU_VGIC_CPU,         offsetof(struct kvm_vcpu, arch.vgic_cpu));
+  DEFINE(VGIC_CPU_HCR,          offsetof(struct vgic_cpu, vgic_hcr));
+  DEFINE(VGIC_CPU_VMCR,         offsetof(struct vgic_cpu, vgic_vmcr));
+  DEFINE(VGIC_CPU_MISR,         offsetof(struct vgic_cpu, vgic_misr));
+  DEFINE(VGIC_CPU_EISR,         offsetof(struct vgic_cpu, vgic_eisr));
+  DEFINE(VGIC_CPU_ELRSR,        offsetof(struct vgic_cpu, vgic_elrsr));
+  DEFINE(VGIC_CPU_APR,          offsetof(struct vgic_cpu, vgic_apr));
+  DEFINE(VGIC_CPU_LR,           offsetof(struct vgic_cpu, vgic_lr));
+  DEFINE(VGIC_CPU_NR_LR,        offsetof(struct vgic_cpu, nr_lr));
+  DEFINE(KVM_VGIC_VCTRL,        offsetof(struct kvm, arch.vgic.vctrl_base));
+#endif
   DEFINE(KVM_VTTBR,             offsetof(struct kvm, arch.vttbr));
 #endif
   return 0; 
diff --git a/arch/arm/kvm/interrupts_head.S b/arch/arm/kvm/interrupts_head.S
index 6a95d341e9c5..8c875d54a089 100644
--- a/arch/arm/kvm/interrupts_head.S
+++ b/arch/arm/kvm/interrupts_head.S
@@ -1,3 +1,5 @@
+#include <linux/irqchip/arm-gic.h>
+
 #define VCPU_USR_REG(_reg_nr)   (VCPU_USR_REGS + (_reg_nr * 4))
 #define VCPU_USR_SP             (VCPU_USR_REG(13))
 #define VCPU_USR_LR             (VCPU_USR_REG(14))
@@ -369,6 +371,49 @@ vcpu	.req	r0		@ vcpu pointer always in r0
  * Assumes vcpu pointer in vcpu reg
  */
 .macro save_vgic_state
+#ifdef CONFIG_KVM_ARM_VGIC
+        /* Get VGIC VCTRL base into r2 */
+        ldr     r2, [vcpu, #VCPU_KVM]
+        ldr     r2, [r2, #KVM_VGIC_VCTRL]
+        cmp     r2, #0
+        beq     2f
+
+        /* Compute the address of struct vgic_cpu */
+        add     r11, vcpu, #VCPU_VGIC_CPU
+
+        /* Save all interesting registers */
+        ldr     r3, [r2, #GICH_HCR]
+        ldr     r4, [r2, #GICH_VMCR]
+        ldr     r5, [r2, #GICH_MISR]
+        ldr     r6, [r2, #GICH_EISR0]
+        ldr     r7, [r2, #GICH_EISR1]
+        ldr     r8, [r2, #GICH_ELRSR0]
+        ldr     r9, [r2, #GICH_ELRSR1]
+        ldr     r10, [r2, #GICH_APR]
+
+        str     r3, [r11, #VGIC_CPU_HCR]
+        str     r4, [r11, #VGIC_CPU_VMCR]
+        str     r5, [r11, #VGIC_CPU_MISR]
+        str     r6, [r11, #VGIC_CPU_EISR]
+        str     r7, [r11, #(VGIC_CPU_EISR + 4)]
+        str     r8, [r11, #VGIC_CPU_ELRSR]
+        str     r9, [r11, #(VGIC_CPU_ELRSR + 4)]
+        str     r10, [r11, #VGIC_CPU_APR]
+
+        /* Clear GICH_HCR */
+        mov     r5, #0
+        str     r5, [r2, #GICH_HCR]
+
+        /* Save list registers */
+        add     r2, r2, #GICH_LR0
+        add     r3, r11, #VGIC_CPU_LR
+        ldr     r4, [r11, #VGIC_CPU_NR_LR]
+1:      ldr     r6, [r2], #4
+        str     r6, [r3], #4
+        subs    r4, r4, #1
+        bne     1b
+2:
+#endif
 .endm
 
 /*
@@ -377,6 +422,35 @@ vcpu	.req	r0		@ vcpu pointer always in r0
  * Assumes vcpu pointer in vcpu reg
  */
 .macro restore_vgic_state
+#ifdef CONFIG_KVM_ARM_VGIC
+        /* Get VGIC VCTRL base into r2 */
+        ldr     r2, [vcpu, #VCPU_KVM]
+        ldr     r2, [r2, #KVM_VGIC_VCTRL]
+        cmp     r2, #0
+        beq     2f
+
+        /* Compute the address of struct vgic_cpu */
+        add     r11, vcpu, #VCPU_VGIC_CPU
+
+        /* We only restore a minimal set of registers */
+        ldr     r3, [r11, #VGIC_CPU_HCR]
+        ldr     r4, [r11, #VGIC_CPU_VMCR]
+        ldr     r8, [r11, #VGIC_CPU_APR]
+
+        str     r3, [r2, #GICH_HCR]
+        str     r4, [r2, #GICH_VMCR]
+        str     r8, [r2, #GICH_APR]
+
+        /* Restore list registers */
+        add     r2, r2, #GICH_LR0
+        add     r3, r11, #VGIC_CPU_LR
+        ldr     r4, [r11, #VGIC_CPU_NR_LR]
+1:      ldr     r6, [r3], #4
+        str     r6, [r2], #4
+        subs    r4, r4, #1
+        bne     1b
+2:
+#endif
 .endm
 
 .equ vmentry,   0