Commit 6ca1a2ca authored by Bibo Mao's avatar Bibo Mao Committed by Xianglai Li
Browse files

LoongArch: KVM: Add PV steal time support in host side 

mainline inclusion
from mainline-v6.11-rc1
commit b4ba157044ea433a66126603ad7140e12dbc794b
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/IAZJDO


CVE: NA

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

Add ParaVirt steal time feature in host side, VM can search supported
features provided by KVM hypervisor, a 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 this feature.

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

Signed-off-by: default avatarBibo Mao <maobibo@loongson.cn>
Signed-off-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
Signed-off-by: default avatarXianglai Li <lixianglai@loongson.cn>
parent 0f720584

arch/loongarch/include/asm/kvm_host.h

+1 −1
Original line number Diff line number Diff line
@@ -34,7 +34,7 @@ 


#define KVM_HALT_POLL_NS_DEFAULT	500000

#define KVM_REQ_TLB_FLUSH_GPA		KVM_ARCH_REQ(0)

#define KVM_REQ_RECORD_STEAL		KVM_ARCH_REQ(1)

#define KVM_REQ_STEAL_UPDATE		KVM_ARCH_REQ(1)



#define KVM_GUESTDBG_SW_BP_MASK		\

	(KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP)

arch/loongarch/include/asm/kvm_para.h

+1 −0
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ struct kvm_steal_time { 
	__u32 pad[12];

};





/*

 * Hypercall interface for KVM hypervisor

 *

arch/loongarch/include/asm/kvm_vcpu.h

+5 −0
Original line number Diff line number Diff line
@@ -120,4 +120,9 @@ static inline void kvm_write_reg(struct kvm_vcpu *vcpu, int num, unsigned long v 
	vcpu->arch.gprs[num] = val;

}



static inline bool kvm_pvtime_supported(void)

{

	return !!sched_info_on();

}



#endif /* __ASM_LOONGARCH_KVM_VCPU_H__ */

arch/loongarch/kvm/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ config KVM 
	select KVM_GENERIC_HARDWARE_ENABLING

	select KVM_MMIO

	select KVM_XFER_TO_GUEST_WORK

	select SCHED_INFO

	select MMU_NOTIFIER

	select PREEMPT_NOTIFIERS

	help

arch/loongarch/kvm/exit.c

+29 −26
Original line number Diff line number Diff line
@@ -259,12 +259,9 @@ static int kvm_emu_cpucfg(struct kvm_vcpu *vcpu, larch_inst inst) 
			vcpu->arch.gprs[rd] = 0;

		break;

	case CPUCFG_KVM_FEATURE:

		ret = 0;

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

			ret = KVM_FEATURE_PV_IPI;

			if (sched_info_on())

		ret = KVM_FEATURE_IPI;

		if (kvm_pvtime_supported())

			ret |= KVM_FEATURE_STEAL_TIME;

		}

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

		break;

	default:
@@ -742,6 +739,31 @@ static int kvm_handle_fpu_disabled(struct kvm_vcpu *vcpu) 
	return RESUME_GUEST;

}



static long kvm_save_notify(struct kvm_vcpu *vcpu)

{

	unsigned long id, data;



	id   = kvm_read_reg(vcpu, LOONGARCH_GPR_A1);

	data = kvm_read_reg(vcpu, LOONGARCH_GPR_A2);

	switch (id) {

	case BIT(KVM_FEATURE_STEAL_TIME):

		if (data & ~(KVM_STEAL_PHYS_MASK | KVM_STEAL_PHYS_VALID))

			return KVM_HCALL_INVALID_PARAMETER;



		vcpu->arch.st.guest_addr = data;

		if (!(data & KVM_STEAL_PHYS_VALID))

			return 0;



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

		kvm_make_request(KVM_REQ_STEAL_UPDATE, vcpu);

		return 0;

	default:

		return KVM_HCALL_INVALID_CODE;

	};



	return KVM_HCALL_INVALID_CODE;

};



/*

 * kvm_handle_lsx_disabled() - Guest used LSX while disabled in root.

 * @vcpu:      Virtual CPU context.
@@ -821,25 +843,6 @@ static void kvm_handle_service(struct kvm_vcpu *vcpu) 
	kvm_write_reg(vcpu, LOONGARCH_GPR_A0, ret);

}



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;

};



static int kvm_handle_hypercall(struct kvm_vcpu *vcpu)

{

	int ret;
@@ -865,7 +868,7 @@ static int kvm_handle_hypercall(struct kvm_vcpu *vcpu) 
		fallthrough;

	default:

		/* Treat it as noop intruction, only set return value */

		vcpu->arch.gprs[LOONGARCH_GPR_A0] = KVM_HCALL_INVALID_CODE;

		kvm_write_reg(vcpu, LOONGARCH_GPR_A0, KVM_HCALL_INVALID_CODE);

		break;

	}