Commit faa35b0f authored by Bibo Mao's avatar Bibo Mao Committed by Xianglai Li
Browse files

LoongArch: KVM: Add steal time support in kvm side 

LoongArch inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I9BTWW

------------------------------------------

Steal time feature is added here in kvm side, VM can search supported
features provided by KVM hypervisor, feature KVM_FEATURE_STEAL_TIME
is added here. Like x86, steal time structure is saved in guest memory,
one hypercall function KVM_HCALL_FUNC_NOTIFY is added to notify KVM to
enable the feature.

One cpu attr ioctl command KVM_LOONGARCH_VCPU_PVTIME_CTRL is added to
save and restore base address of steal time structure when VM is migrated.

Since it needs hypercall instruction emulation handling, and it is
dependent on this patchset:
https://lore.kernel.org/all/20240201031950.3225626-1-maobibo@loongson.cn/



Signed-off-by: default avatarBibo Mao <maobibo@loongson.cn>
Signed-off-by: default avatarXianglai Li <lixianglai@loongson.cn>
parent 5d97cff7

arch/loongarch/include/asm/kvm_host.h

+7 −0
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
#define KVM_PRIVATE_MEM_SLOTS		0



#define KVM_HALT_POLL_NS_DEFAULT	500000

#define KVM_REQ_RECORD_STEAL		KVM_ARCH_REQ(1)



#define KVM_GUESTDBG_VALID_MASK		(KVM_GUESTDBG_ENABLE | \

			KVM_GUESTDBG_USE_SW_BP | KVM_GUESTDBG_SINGLESTEP)
@@ -197,6 +198,12 @@ struct kvm_vcpu_arch { 
	struct kvm_mp_state mp_state;

	/* cpucfg */

	u32 cpucfg[KVM_MAX_CPUCFG_REGS];

	/* paravirt steal time */

	struct {

		u64 guest_addr;

		u64 last_steal;

		struct gfn_to_hva_cache cache;

	} st;

};



static inline unsigned long readl_sw_gcsr(struct loongarch_csrs *csr, int reg)

arch/loongarch/include/asm/kvm_para.h

+10 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 
#define KVM_HCALL_CODE_SWDBG		1

#define KVM_HCALL_PV_SERVICE		HYPERCALL_CODE(HYPERVISOR_KVM, KVM_HCALL_CODE_PV_SERVICE)

#define  KVM_HCALL_FUNC_PV_IPI		1

#define  KVM_HCALL_FUNC_NOTIFY		2

#define KVM_HCALL_SWDBG			HYPERCALL_CODE(HYPERVISOR_KVM, KVM_HCALL_CODE_SWDBG)



/*
@@ -21,6 +22,15 @@ 
#define KVM_HCALL_INVALID_CODE		-1UL

#define KVM_HCALL_INVALID_PARAMETER	-2UL



#define KVM_STEAL_PHYS_VALID		BIT_ULL(0)

#define KVM_STEAL_PHYS_MASK		GENMASK_ULL(63, 6)

struct kvm_steal_time {

	__u64 steal;

	__u32 version;

	__u32 flags;

	__u32 pad[12];

};



/*

 * Hypercall interface for KVM hypervisor

 *

arch/loongarch/include/asm/loongarch.h

+1 −0
Original line number Diff line number Diff line
@@ -168,6 +168,7 @@ 
#define  KVM_SIGNATURE			"KVM\0"

#define CPUCFG_KVM_FEATURE		(CPUCFG_KVM_BASE + 4)

#define  KVM_FEATURE_PV_IPI		BIT(1)

#define  KVM_FEATURE_STEAL_TIME		BIT(2)



#ifndef __ASSEMBLY__

arch/loongarch/include/uapi/asm/kvm.h

+4 −0
Original line number Diff line number Diff line
@@ -83,7 +83,11 @@ struct kvm_fpu { 
#define LOONGARCH_REG_64(TYPE, REG)	(TYPE | KVM_REG_SIZE_U64 | (REG << LOONGARCH_REG_SHIFT))

#define KVM_IOC_CSRID(REG)		LOONGARCH_REG_64(KVM_REG_LOONGARCH_CSR, REG)

#define KVM_IOC_CPUCFG(REG)		LOONGARCH_REG_64(KVM_REG_LOONGARCH_CPUCFG, REG)



/* Device Control API on vcpu fd */

#define KVM_LOONGARCH_VCPU_CPUCFG	0

#define KVM_LOONGARCH_VCPU_PVTIME_CTRL	1

#define  KVM_LOONGARCH_VCPU_PVTIME_GPA	0



struct kvm_debug_exit_arch {

};

arch/loongarch/kvm/exit.c

+30 −5
Original line number Diff line number Diff line
@@ -209,7 +209,7 @@ int kvm_emu_idle(struct kvm_vcpu *vcpu) 
static int kvm_emu_cpucfg(struct kvm_vcpu *vcpu, larch_inst inst)

{

	int rd, rj;

	unsigned int index;

	unsigned int index, ret;

	unsigned long plv;



	rd = inst.reg2_format.rd;
@@ -240,10 +240,13 @@ static int kvm_emu_cpucfg(struct kvm_vcpu *vcpu, larch_inst inst) 
			vcpu->arch.gprs[rd] = 0;

		break;

	case CPUCFG_KVM_FEATURE:

		if ((plv & CSR_CRMD_PLV) == PLV_KERN)

			vcpu->arch.gprs[rd] = KVM_FEATURE_PV_IPI;

		else

			vcpu->arch.gprs[rd] = 0;

		ret = 0;

		if ((plv & CSR_CRMD_PLV) == PLV_KERN) {

			ret = KVM_FEATURE_PV_IPI;

			if (sched_info_on())

				ret |= KVM_FEATURE_STEAL_TIME;

		}

		vcpu->arch.gprs[rd] = ret;

		break;

	default:

		vcpu->arch.gprs[rd] = 0;
@@ -749,6 +752,25 @@ static int kvm_pv_send_ipi(struct kvm_vcpu *vcpu) 
	return 0;

}



static int kvm_save_notify(struct kvm_vcpu *vcpu)

{

	unsigned long id, data;



	id = vcpu->arch.gprs[LOONGARCH_GPR_A1];

	data = vcpu->arch.gprs[LOONGARCH_GPR_A2];

	switch (id) {

	case KVM_FEATURE_STEAL_TIME:

		vcpu->arch.st.guest_addr = data;

		vcpu->arch.st.last_steal = current->sched_info.run_delay;

		kvm_make_request(KVM_REQ_RECORD_STEAL, vcpu);

		break;

	default:

		break;

	};



	return 0;

};



/*

 * hypercall emulation always return to guest, Caller should check retval.

 */
@@ -762,6 +784,9 @@ static void kvm_handle_pv_service(struct kvm_vcpu *vcpu) 
		kvm_pv_send_ipi(vcpu);

		ret = KVM_HCALL_STATUS_SUCCESS;

		break;

	case KVM_HCALL_FUNC_NOTIFY:

		ret = kvm_save_notify(vcpu);

		break;

	default:

		ret = KVM_HCALL_INVALID_CODE;

		break;