Commit ac30a11e authored by Marc Zyngier's avatar Marc Zyngier
Browse files

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: default avatarMarc Zyngier <marc.zyngier@arm.com>
Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 547f7813

arch/arm/include/asm/kvm_arm.h

+0 −1
Original line number Diff line number Diff line
@@ -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)

arch/arm/include/asm/kvm_host.h

+6 −3
Original line number Diff line number Diff line
@@ -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;

arch/arm/kernel/asm-offsets.c

+1 −0
Original line number Diff line number Diff line
@@ -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));

arch/arm/kvm/guest.c

+1 −0
Original line number Diff line number Diff line
@@ -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;

}

arch/arm/kvm/interrupts_head.S

+3 −6
Original line number Diff line number Diff line
@@ -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

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