[PATCH 3.14 45/51] ARM: KVM: introduce per-vcpu HYP Configuration Register

Greg Kroah-Hartman
2015-05-15T23:14:19Z

From: Marc Zyngier <marc.zyngier@arm.com>

commit ac30a11e8e92a03dbe236b285c5cbae0bf563141 upstream.

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>
Cc: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/arm/include/asm/kvm_arm.h | 1 -
arch/arm/include/asm/kvm_host.h | 9 ++++++---
arch/arm/kernel/asm-offsets.c | 1 +
arch/arm/kvm/guest.c | 1 +
arch/arm/kvm/interrupts_head.S | 9 +++------
5 files changed, 11 insertions(+), 10 deletions(-)

--- 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)
--- 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;

--- 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));
--- a/arch/arm/kvm/guest.c
+++ b/arch/arm/kvm/guest.c
@@ -38,6 +38,7 @@ struct kvm_stats_debugfs_item debugfs_en

int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
{
+ vcpu->arch.hcr = HCR_GUEST_MASK;
return 0;
}

--- 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 r

/* 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