Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f7f1427d authored by James Hogan's avatar James Hogan
Browse files

KVM: MIPS/T&E: Allocate GVA -> HPA page tables 



Allocate GVA -> HPA page tables for guest kernel and guest user mode on
each VCPU, to allow for fast path TLB refill handling to be added later.

In the process kvm_arch_vcpu_init() needs updating to pass on any error
from the vcpu_init() callback.

Signed-off-by: default avatarJames Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
parent 630766b3

arch/mips/kvm/mips.c

+6 −1
Original line number Diff line number Diff line
@@ -1338,7 +1338,12 @@ static enum hrtimer_restart kvm_mips_comparecount_wakeup(struct hrtimer *timer) 


int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)

{

	kvm_mips_callbacks->vcpu_init(vcpu);

	int err;



	err = kvm_mips_callbacks->vcpu_init(vcpu);

	if (err)

		return err;



	hrtimer_init(&vcpu->arch.comparecount_timer, CLOCK_MONOTONIC,

		     HRTIMER_MODE_REL);

	vcpu->arch.comparecount_timer.function = kvm_mips_comparecount_wakeup;

arch/mips/kvm/trap_emul.c

+63 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/kvm_host.h>

#include <linux/vmalloc.h>

#include <asm/mmu_context.h>

#include <asm/pgalloc.h>



#include "interrupt.h"
@@ -435,13 +436,75 @@ static int kvm_trap_emul_vm_init(struct kvm *kvm) 


static int kvm_trap_emul_vcpu_init(struct kvm_vcpu *vcpu)

{

	struct mm_struct *kern_mm = &vcpu->arch.guest_kernel_mm;

	struct mm_struct *user_mm = &vcpu->arch.guest_user_mm;



	vcpu->arch.kscratch_enabled = 0xfc;



	/*

	 * Allocate GVA -> HPA page tables.

	 * MIPS doesn't use the mm_struct pointer argument.

	 */

	kern_mm->pgd = pgd_alloc(kern_mm);

	if (!kern_mm->pgd)

		return -ENOMEM;



	user_mm->pgd = pgd_alloc(user_mm);

	if (!user_mm->pgd) {

		pgd_free(kern_mm, kern_mm->pgd);

		return -ENOMEM;

	}



	return 0;

}



static void kvm_mips_emul_free_gva_pt(pgd_t *pgd)

{

	/* Don't free host kernel page tables copied from init_mm.pgd */

	const unsigned long end = 0x80000000;

	unsigned long pgd_va, pud_va, pmd_va;

	pud_t *pud;

	pmd_t *pmd;

	pte_t *pte;

	int i, j, k;



	for (i = 0; i < USER_PTRS_PER_PGD; i++) {

		if (pgd_none(pgd[i]))

			continue;



		pgd_va = (unsigned long)i << PGDIR_SHIFT;

		if (pgd_va >= end)

			break;

		pud = pud_offset(pgd + i, 0);

		for (j = 0; j < PTRS_PER_PUD; j++) {

			if (pud_none(pud[j]))

				continue;



			pud_va = pgd_va | ((unsigned long)j << PUD_SHIFT);

			if (pud_va >= end)

				break;

			pmd = pmd_offset(pud + j, 0);

			for (k = 0; k < PTRS_PER_PMD; k++) {

				if (pmd_none(pmd[k]))

					continue;



				pmd_va = pud_va | (k << PMD_SHIFT);

				if (pmd_va >= end)

					break;

				pte = pte_offset(pmd + k, 0);

				pte_free_kernel(NULL, pte);

			}

			pmd_free(NULL, pmd);

		}

		pud_free(NULL, pud);

	}

	pgd_free(NULL, pgd);

}



static void kvm_trap_emul_vcpu_uninit(struct kvm_vcpu *vcpu)

{

	kvm_mips_emul_free_gva_pt(vcpu->arch.guest_kernel_mm.pgd);

	kvm_mips_emul_free_gva_pt(vcpu->arch.guest_user_mm.pgd);

}



static int kvm_trap_emul_vcpu_setup(struct kvm_vcpu *vcpu)