diff mbox series

[RFC,32/32] KVM: PPC: Book3S HV: Add nested shadow page tables to debugfs

Message ID 1537524123-9578-33-git-send-email-paulus@ozlabs.org (mailing list archive)
State New, archived
Headers show
Series KVM: PPC: Book3S HV: Nested HV virtualization | expand

Commit Message

Paul Mackerras Sept. 21, 2018, 10:02 a.m. UTC
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@ozlabs.org>
---
 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(-)

Comments

David Gibson Sept. 27, 2018, 5:01 a.m. UTC | #1
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@ozlabs.org>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

> ---
>  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;
> +}
diff mbox series

Patch

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;
+}