Commit a33c72fa authored by Anup Patel's avatar Anup Patel Committed by Anup Patel
Browse files

RISC-V: KVM: Implement VCPU create, init and destroy functions 



This patch implements VCPU create, init and destroy functions
required by generic KVM module. We don't have much dynamic
resources in struct kvm_vcpu_arch so these functions are quite
simple for KVM RISC-V.

Signed-off-by: default avatarAnup Patel <anup.patel@wdc.com>
Acked-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: default avatarAlexander Graf <graf@amazon.com>
Acked-by: default avatarPalmer Dabbelt <palmerdabbelt@google.com>
parent 99cdc6c1

arch/riscv/include/asm/kvm_host.h

+69 −0
Original line number Diff line number Diff line
@@ -57,7 +57,76 @@ struct kvm_cpu_trap { 
	unsigned long htinst;

};



struct kvm_cpu_context {

	unsigned long zero;

	unsigned long ra;

	unsigned long sp;

	unsigned long gp;

	unsigned long tp;

	unsigned long t0;

	unsigned long t1;

	unsigned long t2;

	unsigned long s0;

	unsigned long s1;

	unsigned long a0;

	unsigned long a1;

	unsigned long a2;

	unsigned long a3;

	unsigned long a4;

	unsigned long a5;

	unsigned long a6;

	unsigned long a7;

	unsigned long s2;

	unsigned long s3;

	unsigned long s4;

	unsigned long s5;

	unsigned long s6;

	unsigned long s7;

	unsigned long s8;

	unsigned long s9;

	unsigned long s10;

	unsigned long s11;

	unsigned long t3;

	unsigned long t4;

	unsigned long t5;

	unsigned long t6;

	unsigned long sepc;

	unsigned long sstatus;

	unsigned long hstatus;

};



struct kvm_vcpu_csr {

	unsigned long vsstatus;

	unsigned long vsie;

	unsigned long vstvec;

	unsigned long vsscratch;

	unsigned long vsepc;

	unsigned long vscause;

	unsigned long vstval;

	unsigned long hvip;

	unsigned long vsatp;

	unsigned long scounteren;

};



struct kvm_vcpu_arch {

	/* VCPU ran at least once */

	bool ran_atleast_once;



	/* ISA feature bits (similar to MISA) */

	unsigned long isa;



	/* CPU context of Guest VCPU */

	struct kvm_cpu_context guest_context;



	/* CPU CSR context of Guest VCPU */

	struct kvm_vcpu_csr guest_csr;



	/* CPU context upon Guest VCPU reset */

	struct kvm_cpu_context guest_reset_context;



	/* CPU CSR context upon Guest VCPU reset */

	struct kvm_vcpu_csr guest_reset_csr;



	/* Don't run the VCPU (blocked) */

	bool pause;

arch/riscv/kvm/vcpu.c

+46 −9
Original line number Diff line number Diff line
@@ -38,6 +38,27 @@ const struct kvm_stats_header kvm_vcpu_stats_header = { 
		       sizeof(kvm_vcpu_stats_desc),

};



#define KVM_RISCV_ISA_ALLOWED	(riscv_isa_extension_mask(a) | \

				 riscv_isa_extension_mask(c) | \

				 riscv_isa_extension_mask(d) | \

				 riscv_isa_extension_mask(f) | \

				 riscv_isa_extension_mask(i) | \

				 riscv_isa_extension_mask(m) | \

				 riscv_isa_extension_mask(s) | \

				 riscv_isa_extension_mask(u))



static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu)

{

	struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;

	struct kvm_vcpu_csr *reset_csr = &vcpu->arch.guest_reset_csr;

	struct kvm_cpu_context *cntx = &vcpu->arch.guest_context;

	struct kvm_cpu_context *reset_cntx = &vcpu->arch.guest_reset_context;



	memcpy(csr, reset_csr, sizeof(*csr));



	memcpy(cntx, reset_cntx, sizeof(*cntx));

}



int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)

{

	return 0;
@@ -45,7 +66,25 @@ int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id) 


int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)

{

	/* TODO: */

	struct kvm_cpu_context *cntx;



	/* Mark this VCPU never ran */

	vcpu->arch.ran_atleast_once = false;



	/* Setup ISA features available to VCPU */

	vcpu->arch.isa = riscv_isa_extension_base(NULL) & KVM_RISCV_ISA_ALLOWED;



	/* Setup reset state of shadow SSTATUS and HSTATUS CSRs */

	cntx = &vcpu->arch.guest_reset_context;

	cntx->sstatus = SR_SPP | SR_SPIE;

	cntx->hstatus = 0;

	cntx->hstatus |= HSTATUS_VTW;

	cntx->hstatus |= HSTATUS_SPVP;

	cntx->hstatus |= HSTATUS_SPV;



	/* Reset VCPU */

	kvm_riscv_reset_vcpu(vcpu);



	return 0;

}
@@ -53,15 +92,10 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu) 
{

}



int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)

{

	/* TODO: */

	return 0;

}



void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)

{

	/* TODO: */

	/* Flush the pages pre-allocated for Stage2 page table mappings */

	kvm_riscv_stage2_flush_cache(vcpu);

}



int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
@@ -197,6 +231,9 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) 
	struct kvm_cpu_trap trap;

	struct kvm_run *run = vcpu->run;



	/* Mark this VCPU ran at least once */

	vcpu->arch.ran_atleast_once = true;



	vcpu->arch.srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);



	/* Process MMIO value returned from user-space */
@@ -270,7 +307,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) 
		 * get an interrupt between __kvm_riscv_switch_to() and

		 * local_irq_enable() which can potentially change CSRs.

		 */

		trap.sepc = 0;

		trap.sepc = vcpu->arch.guest_context.sepc;

		trap.scause = csr_read(CSR_SCAUSE);

		trap.stval = csr_read(CSR_STVAL);

		trap.htval = csr_read(CSR_HTVAL);