On Fri, Sep 21, 2018 at 08:02:03PM +1000, Paul Mackerras wrote:
> This adds a list of valid shadow PTEs for each nested guest to
> the 'radix' file for the guest in debugfs. This can be useful for
> debugging.
>
> Signed-off-by: Paul Mackerras <paulus@xxxxxxxxxx>
Reviewed-by: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
> ---
> arch/powerpc/include/asm/kvm_book3s_64.h | 1 +
> arch/powerpc/kvm/book3s_64_mmu_radix.c | 39 +++++++++++++++++++++++++++++---
> arch/powerpc/kvm/book3s_hv_nested.c | 15 ++++++++++++
> 3 files changed, 52 insertions(+), 3 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
> index 84c4c0e..12007f6 100644
> --- a/arch/powerpc/include/asm/kvm_book3s_64.h
> +++ b/arch/powerpc/include/asm/kvm_book3s_64.h
> @@ -50,6 +50,7 @@ struct rmap_nested {
> struct kvm_nested_guest *kvmhv_get_nested(struct kvm *kvm, int lpid,
> bool create);
> void kvmhv_put_nested(struct kvm_nested_guest *gp);
> +int kvmhv_nested_next_lpid(struct kvm *kvm, int lpid);
>
> /* Power architecture requires HPT is at least 256kiB, at most 64TiB */
> #define PPC_MIN_HPT_ORDER 18
> diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
> index 52b2a57..41beb9b 100644
> --- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
> +++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
> @@ -978,6 +978,7 @@ struct debugfs_radix_state {
> struct kvm *kvm;
> struct mutex mutex;
> unsigned long gpa;
> + int lpid;
> int chars_left;
> int buf_index;
> char buf[128];
> @@ -1019,6 +1020,7 @@ static ssize_t debugfs_radix_read(struct file *file, char __user *buf,
> struct kvm *kvm;
> unsigned long gpa;
> pgd_t *pgt;
> + struct kvm_nested_guest *nested;
> pgd_t pgd, *pgdp;
> pud_t pud, *pudp;
> pmd_t pmd, *pmdp;
> @@ -1053,10 +1055,39 @@ static ssize_t debugfs_radix_read(struct file *file, char __user *buf,
> }
>
> gpa = p->gpa;
> - pgt = kvm->arch.pgtable;
> - while (len != 0 && gpa < RADIX_PGTABLE_RANGE) {
> + nested = NULL;
> + pgt = NULL;
> + while (len != 0 && p->lpid >= 0) {
> + if (gpa >= RADIX_PGTABLE_RANGE) {
> + gpa = 0;
> + pgt = NULL;
> + if (nested) {
> + kvmhv_put_nested(nested);
> + nested = NULL;
> + }
> + p->lpid = kvmhv_nested_next_lpid(kvm, p->lpid);
> + p->hdr = 0;
> + if (p->lpid < 0)
> + break;
> + }
> + if (!pgt) {
> + if (p->lpid == 0) {
> + pgt = kvm->arch.pgtable;
> + } else {
> + nested = kvmhv_get_nested(kvm, p->lpid, false);
> + if (!nested) {
> + gpa = RADIX_PGTABLE_RANGE;
> + continue;
> + }
> + pgt = nested->shadow_pgtable;
> + }
> + }
> + n = 0;
> if (!p->hdr) {
> - n = scnprintf(p->buf, sizeof(p->buf),
> + if (p->lpid > 0)
> + n = scnprintf(p->buf, sizeof(p->buf),
> + "\nNested LPID %d: ", p->lpid);
> + n += scnprintf(p->buf + n, sizeof(p->buf) - n,
> "pgdir: %lx\n", (unsigned long)pgt);
> p->hdr = 1;
> goto copy;
> @@ -1122,6 +1153,8 @@ static ssize_t debugfs_radix_read(struct file *file, char __user *buf,
> }
> }
> p->gpa = gpa;
> + if (nested)
> + kvmhv_put_nested(nested);
>
> out:
> mutex_unlock(&p->mutex);
> diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
> index 0d7cd66..027cc16 100644
> --- a/arch/powerpc/kvm/book3s_hv_nested.c
> +++ b/arch/powerpc/kvm/book3s_hv_nested.c
> @@ -1182,3 +1182,18 @@ long int kvmhv_nested_page_fault(struct kvm_vcpu *vcpu)
> mutex_unlock(&gp->tlb_lock);
> return ret;
> }
> +
> +int kvmhv_nested_next_lpid(struct kvm *kvm, int lpid)
> +{
> + int ret = -1;
> +
> + spin_lock(&kvm->mmu_lock);
> + while (++lpid <= kvm->arch.max_nested_lpid) {
> + if (kvm->arch.nested_guests[lpid]) {
> + ret = lpid;
> + break;
> + }
> + }
> + spin_unlock(&kvm->mmu_lock);
> + return ret;
> +}
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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