ARM: KVM: introduce per-vcpu HYP Configuration Register

So far, KVM/ARM used a fixed HCR configuration per guest, except for
the VI/VF/VA bits to control the interrupt in absence of VGIC.

With the upcoming need to dynamically reconfigure trapping, it becomes
necessary to allow the HCR to be changed on a per-vcpu basis.

The fix here is to mimic what KVM/arm64 already does: a per vcpu HCR
field, initialized at setup time.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h
index 1d3153c..a843e74 100644 (file)
--- a/arch/arm/include/asm/kvm_arm.h
+++ b/arch/arm/include/asm/kvm_arm.h
@@ -69,7 +69,6 @@
 #define HCR_GUEST_MASK (HCR_TSC | HCR_TSW | HCR_TWI | HCR_VM | HCR_BSU_IS | \
                        HCR_FB | HCR_TAC | HCR_AMO | HCR_IMO | HCR_FMO | \
                        HCR_TWE | HCR_SWIO | HCR_TIDCP)
-#define HCR_VIRT_EXCP_MASK (HCR_VA | HCR_VI | HCR_VF)
 
 /* System Control Register (SCTLR) bits */
 #define SCTLR_TE       (1 << 30)

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 098f7dd..09af149 100644 (file)
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -101,6 +101,12 @@ struct kvm_vcpu_arch {
        /* The CPU type we expose to the VM */
        u32 midr;
 
+       /* HYP trapping configuration */
+       u32 hcr;
+
+       /* Interrupt related fields */
+       u32 irq_lines;          /* IRQ and FIQ levels */
+
        /* Exception Information */
        struct kvm_vcpu_fault_info fault;
 
@@ -128,9 +134,6 @@ struct kvm_vcpu_arch {
        /* IO related fields */
        struct kvm_decode mmio_decode;
 
-       /* Interrupt related fields */
-       u32 irq_lines;          /* IRQ and FIQ levels */
-
        /* Cache some mmu pages needed inside spinlock regions */
        struct kvm_mmu_memory_cache mmu_page_cache;
 

diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
index ded0417..85598b5 100644 (file)
--- a/arch/arm/kernel/asm-offsets.c
+++ b/arch/arm/kernel/asm-offsets.c
@@ -174,6 +174,7 @@ int main(void)
   DEFINE(VCPU_FIQ_REGS,                offsetof(struct kvm_vcpu, arch.regs.fiq_regs));
   DEFINE(VCPU_PC,              offsetof(struct kvm_vcpu, arch.regs.usr_regs.ARM_pc));
   DEFINE(VCPU_CPSR,            offsetof(struct kvm_vcpu, arch.regs.usr_regs.ARM_cpsr));
+  DEFINE(VCPU_HCR,             offsetof(struct kvm_vcpu, arch.hcr));
   DEFINE(VCPU_IRQ_LINES,       offsetof(struct kvm_vcpu, arch.irq_lines));
   DEFINE(VCPU_HSR,             offsetof(struct kvm_vcpu, arch.fault.hsr));
   DEFINE(VCPU_HxFAR,           offsetof(struct kvm_vcpu, arch.fault.hxfar));

diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c
index 2786eae..b23a59c 100644 (file)
--- a/arch/arm/kvm/guest.c
+++ b/arch/arm/kvm/guest.c
@@ -38,6 +38,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
 
 int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
 {
+       vcpu->arch.hcr = HCR_GUEST_MASK;
        return 0;
 }
 

diff --git a/arch/arm/kvm/interrupts_head.S b/arch/arm/kvm/interrupts_head.S
index 6f18695..a37270d 100644 (file)
--- a/arch/arm/kvm/interrupts_head.S
+++ b/arch/arm/kvm/interrupts_head.S
@@ -597,17 +597,14 @@ vcpu      .req    r0              @ vcpu pointer always in r0
 
 /* Enable/Disable: stage-2 trans., trap interrupts, trap wfi, trap smc */
 .macro configure_hyp_role operation
-       mrc     p15, 4, r2, c1, c1, 0   @ HCR
-       bic     r2, r2, #HCR_VIRT_EXCP_MASK
-       ldr     r3, =HCR_GUEST_MASK
        .if \operation == vmentry
-       orr     r2, r2, r3
+       ldr     r2, [vcpu, #VCPU_HCR]
        ldr     r3, [vcpu, #VCPU_IRQ_LINES]
        orr     r2, r2, r3
        .else
-       bic     r2, r2, r3
+       mov     r2, #0
        .endif
-       mcr     p15, 4, r2, c1, c1, 0
+       mcr     p15, 4, r2, c1, c1, 0   @ HCR
 .endm
 
 .macro load_vcpu