Commit 062ac0cb authored by Bibo Mao's avatar Bibo Mao Committed by Huacai Chen
Browse files

LoongArch: KVM: Remove PGD saving during VM context switch 



PGD table for primary mmu keeps unchanged once VM is created, it is not
necessary to save PGD table pointer during VM context switch. And it can
be acquired when VM is created.

Signed-off-by: default avatarBibo Mao <maobibo@loongson.cn>
Signed-off-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
parent 1c405b42

arch/loongarch/include/asm/kvm_host.h

+3 −0
Original line number Diff line number Diff line
@@ -176,6 +176,9 @@ struct kvm_vcpu_arch { 
	/* Pointers stored here for easy accessing from assembly code */

	int (*handle_exit)(struct kvm_run *run, struct kvm_vcpu *vcpu);



	/* GPA (=HVA) of PGD for secondary mmu */

	unsigned long kvm_pgd;



	/* Host registers preserved across guest mode execution */

	unsigned long host_sp;

	unsigned long host_tp;

arch/loongarch/kernel/asm-offsets.c

+1 −0
Original line number Diff line number Diff line
@@ -296,6 +296,7 @@ static void __used output_kvm_defines(void) 
	OFFSET(KVM_ARCH_HSP, kvm_vcpu_arch, host_sp);

	OFFSET(KVM_ARCH_HTP, kvm_vcpu_arch, host_tp);

	OFFSET(KVM_ARCH_HPGD, kvm_vcpu_arch, host_pgd);

	OFFSET(KVM_ARCH_KVMPGD, kvm_vcpu_arch, kvm_pgd);

	OFFSET(KVM_ARCH_HANDLE_EXIT, kvm_vcpu_arch, handle_exit);

	OFFSET(KVM_ARCH_HEENTRY, kvm_vcpu_arch, host_eentry);

	OFFSET(KVM_ARCH_GEENTRY, kvm_vcpu_arch, guest_eentry);

arch/loongarch/kvm/switch.S

+2 −10
Original line number Diff line number Diff line
@@ -60,16 +60,8 @@ 
	ld.d	t0, a2, KVM_ARCH_GPC

	csrwr	t0, LOONGARCH_CSR_ERA



	/* Save host PGDL */

	csrrd	t0, LOONGARCH_CSR_PGDL

	st.d	t0, a2, KVM_ARCH_HPGD



	/* Switch to kvm */

	ld.d	t1, a2, KVM_VCPU_KVM - KVM_VCPU_ARCH



	/* Load guest PGDL */

	li.w    t0, KVM_GPGD

	ldx.d   t0, t1, t0

	/* Load PGD for KVM hypervisor */

	ld.d	t0, a2, KVM_ARCH_KVMPGD

	csrwr	t0, LOONGARCH_CSR_PGDL



	/* Mix GID and RID */

arch/loongarch/kvm/vcpu.c

+9 −0
Original line number Diff line number Diff line
@@ -1462,6 +1462,15 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) 
	hrtimer_init(&vcpu->arch.swtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED_HARD);

	vcpu->arch.swtimer.function = kvm_swtimer_wakeup;



	/* Get GPA (=HVA) of PGD for kvm hypervisor */

	vcpu->arch.kvm_pgd = __pa(vcpu->kvm->arch.pgd);



	/*

	 * Get PGD for primary mmu, virtual address is used since there is

	 * memory access after loading from CSR_PGD in tlb exception fast path.

	 */

	vcpu->arch.host_pgd = (unsigned long)vcpu->kvm->mm->pgd;



	vcpu->arch.handle_exit = kvm_handle_exit;

	vcpu->arch.guest_eentry = (unsigned long)kvm_loongarch_ops->exc_entry;

	vcpu->arch.csr = kzalloc(sizeof(struct loongarch_csrs), GFP_KERNEL);