[PATCH] iommu/vt-d: Add Scalable Mode fault information

[PATCH] iommu/vt-d: Add Scalable Mode fault information

[Kyung Min Park]

Intel VT-d specification revision 3 added support for Scalable Mode
Translation for DMA remapping. Add the Scalable Mode fault reasons to
show detailed fault reasons when the translation fault happens.

Link: https://software.intel.com/sites/default/files/managed/c5/15/vt-directed-io-spec.pdf

Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Kyung Min Park <kyung.min.park@intel.com>
---
 drivers/iommu/dmar.c        | 77 ++++++++++++++++++++++++++++++++++++++++++---
 include/linux/intel-iommu.h |  2 ++
 2 files changed, 75 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 1207e05..5cb63c5 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -1532,6 +1532,64 @@ static const char *dma_remap_fault_reasons[] =
 	"PCE for translation request specifies blocking",
 };
 
+static const char * const dma_remap_sm_fault_reasons[] = {
+	"SM: Invalid Root Table Address",
+	"SM: TTM 0 for request with PASID",
+	"SM: TTM 0 for page group request",
+	"Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x33-0x37 */
+	"SM: Error attempting to access Root Entry",
+	"SM: Present bit in Root Entry is clear",
+	"SM: Non-zero reserved field set in Root Entry",
+	"Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x3B-0x3F */
+	"SM: Error attempting to access Context Entry",
+	"SM: Present bit in Context Entry is clear",
+	"SM: Non-zero reserved field set in the Context Entry",
+	"SM: Invalid Context Entry",
+	"SM: DTE field in Context Entry is clear",
+	"SM: PASID Enable field in Context Entry is clear",
+	"SM: PASID is larger than the max in Context Entry",
+	"SM: PRE field in Context-Entry is clear",
+	"SM: RID_PASID field error in Context-Entry",
+	"Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x49-0x4F */
+	"SM: Error attempting to access the PASID Directory Entry",
+	"SM: Present bit in Directory Entry is clear",
+	"SM: Non-zero reserved field set in PASID Directory Entry",
+	"Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x53-0x57 */
+	"SM: Error attempting to access PASID Table Entry",
+	"SM: Present bit in PASID Table Entry is clear",
+	"SM: Non-zero reserved field set in PASID Table Entry",
+	"SM: Invalid Scalable-Mode PASID Table Entry",
+	"SM: ERE field is clear in PASID Table Entry",
+	"SM: SRE field is clear in PASID Table Entry",
+	"Unknown", "Unknown",/* 0x5E-0x5F */
+	"Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x60-0x67 */
+	"Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x68-0x6F */
+	"SM: Error attempting to access first-level paging entry",
+	"SM: Present bit in first-level paging entry is clear",
+	"SM: Non-zero reserved field set in first-level paging entry",
+	"SM: Error attempting to access FL-PML4 entry",
+	"SM: First-level entry address beyond MGAW in Nested translation",
+	"SM: Read permission error in FL-PML4 entry in Nested translation",
+	"SM: Read permission error in first-level paging entry in Nested translation",
+	"SM: Write permission error in first-level paging entry in Nested translation",
+	"SM: Error attempting to access second-level paging entry",
+	"SM: Read/Write permission error in second-level paging entry",
+	"SM: Non-zero reserved field set in second-level paging entry",
+	"SM: Invalid second-level page table pointer",
+	"SM: A/D bit update needed in second-level entry when set up in no snoop",
+	"Unknown", "Unknown", "Unknown", /* 0x7D-0x7F */
+	"SM: Address in first-level translation is not canonical",
+	"SM: U/S set 0 for first-level translation with user privilege",
+	"SM: No execute permission for request with PASID and ER=1",
+	"SM: Address beyond the DMA hardware max",
+	"SM: Second-level entry address beyond the max",
+	"SM: No write permission for Write/AtomicOp request",
+	"SM: No read permission for Read/AtomicOp request",
+	"SM: Invalid address-interrupt address",
+	"Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x88-0x8F */
+	"SM: A/D bit update needed in first-level entry when set up in no snoop",
+};
+
 static const char *irq_remap_fault_reasons[] =
 {
 	"Detected reserved fields in the decoded interrupt-remapped request",
@@ -1549,6 +1607,10 @@ static const char *dmar_get_fault_reason(u8 fault_reason, int *fault_type)
 					ARRAY_SIZE(irq_remap_fault_reasons))) {
 		*fault_type = INTR_REMAP;
 		return irq_remap_fault_reasons[fault_reason - 0x20];
+	} else if (fault_reason >= 0x30 && (fault_reason - 0x30 <
+			ARRAY_SIZE(dma_remap_sm_fault_reasons))) {
+		*fault_type = DMA_REMAP;
+		return dma_remap_sm_fault_reasons[fault_reason - 0x30];
 	} else if (fault_reason < ARRAY_SIZE(dma_remap_fault_reasons)) {
 		*fault_type = DMA_REMAP;
 		return dma_remap_fault_reasons[fault_reason];
@@ -1624,7 +1686,8 @@ void dmar_msi_read(int irq, struct msi_msg *msg)
 }
 
 static int dmar_fault_do_one(struct intel_iommu *iommu, int type,
-		u8 fault_reason, u16 source_id, unsigned long long addr)
+		u8 fault_reason, int pasid, u16 source_id,
+		unsigned long long addr)
 {
 	const char *reason;
 	int fault_type;
@@ -1637,10 +1700,11 @@ static int dmar_fault_do_one(struct intel_iommu *iommu, int type,
 			PCI_FUNC(source_id & 0xFF), addr >> 48,
 			fault_reason, reason);
 	else
-		pr_err("[%s] Request device [%02x:%02x.%d] fault addr %llx [fault reason %02d] %s\n",
+		pr_err("[%s] Request device [%02x:%02x.%d] PASID %x fault addr %llx [fault reason %02d] %s\n",
 		       type ? "DMA Read" : "DMA Write",
 		       source_id >> 8, PCI_SLOT(source_id & 0xFF),
-		       PCI_FUNC(source_id & 0xFF), addr, fault_reason, reason);
+		       PCI_FUNC(source_id & 0xFF), pasid, addr,
+		       fault_reason, reason);
 	return 0;
 }
 
@@ -1672,8 +1736,9 @@ irqreturn_t dmar_fault(int irq, void *dev_id)
 		u8 fault_reason;
 		u16 source_id;
 		u64 guest_addr;
-		int type;
+		int type, pasid;
 		u32 data;
+		bool pasid_present;
 
 		/* highest 32 bits */
 		data = readl(iommu->reg + reg +
@@ -1685,10 +1750,12 @@ irqreturn_t dmar_fault(int irq, void *dev_id)
 			fault_reason = dma_frcd_fault_reason(data);
 			type = dma_frcd_type(data);
 
+			pasid = dma_frcd_pasid_value(data);
 			data = readl(iommu->reg + reg +
 				     fault_index * PRIMARY_FAULT_REG_LEN + 8);
 			source_id = dma_frcd_source_id(data);
 
+			pasid_present = dma_frcd_pasid_present(data);
 			guest_addr = dmar_readq(iommu->reg + reg +
 					fault_index * PRIMARY_FAULT_REG_LEN);
 			guest_addr = dma_frcd_page_addr(guest_addr);
@@ -1701,7 +1768,9 @@ irqreturn_t dmar_fault(int irq, void *dev_id)
 		raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
 
 		if (!ratelimited)
+			/* Using pasid -1 if pasid is not present */
 			dmar_fault_do_one(iommu, type, fault_reason,
+					  pasid_present ? pasid : -1,
 					  source_id, guest_addr);
 
 		fault_index++;
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 3c6327b..617f68f 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -265,6 +265,8 @@
 #define dma_frcd_type(d) ((d >> 30) & 1)
 #define dma_frcd_fault_reason(c) (c & 0xff)
 #define dma_frcd_source_id(c) (c & 0xffff)
+#define dma_frcd_pasid_value(c) (((c) >> 8) & 0xfffff)
+#define dma_frcd_pasid_present(c) (((c) >> 31) & 1)
 /* low 64 bit */
 #define dma_frcd_page_addr(d) (d & (((u64)-1) << PAGE_SHIFT))
 
-- 
2.7.4

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Re: [PATCH] iommu/vt-d: Add Scalable Mode fault information

[Joerg Roedel]

On Fri, Sep 06, 2019 at 11:14:02AM -0700, Kyung Min Park wrote:
> Intel VT-d specification revision 3 added support for Scalable Mode
> Translation for DMA remapping. Add the Scalable Mode fault reasons to
> show detailed fault reasons when the translation fault happens.
> 
> Link: https://software.intel.com/sites/default/files/managed/c5/15/vt-directed-io-spec.pdf
> 
> Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
> Signed-off-by: Kyung Min Park <kyung.min.park@intel.com>
> ---
>  drivers/iommu/dmar.c        | 77 ++++++++++++++++++++++++++++++++++++++++++---
>  include/linux/intel-iommu.h |  2 ++
>  2 files changed, 75 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
> index 1207e05..5cb63c5 100644
> --- a/drivers/iommu/dmar.c
> +++ b/drivers/iommu/dmar.c
> @@ -1532,6 +1532,64 @@ static const char *dma_remap_fault_reasons[] =
>  	"PCE for translation request specifies blocking",
>  };
>  
> +static const char * const dma_remap_sm_fault_reasons[] = {
> +	"SM: Invalid Root Table Address",
> +	"SM: TTM 0 for request with PASID",
> +	"SM: TTM 0 for page group request",
> +	"Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x33-0x37 */
> +	"SM: Error attempting to access Root Entry",
> +	"SM: Present bit in Root Entry is clear",
> +	"SM: Non-zero reserved field set in Root Entry",
> +	"Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x3B-0x3F */
> +	"SM: Error attempting to access Context Entry",
> +	"SM: Present bit in Context Entry is clear",
> +	"SM: Non-zero reserved field set in the Context Entry",
> +	"SM: Invalid Context Entry",
> +	"SM: DTE field in Context Entry is clear",
> +	"SM: PASID Enable field in Context Entry is clear",
> +	"SM: PASID is larger than the max in Context Entry",
> +	"SM: PRE field in Context-Entry is clear",
> +	"SM: RID_PASID field error in Context-Entry",
> +	"Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x49-0x4F */

Maybe add the number (0x49-0x4f) to the respecting "Unknown" fields? If
we can't give a reason we should give the number for easier debugging in
the future. Same for the "Unknown" fields below.

Other than that, the patch looks good.

Regards,

	Joerg
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Re: [PATCH] iommu/vt-d: Add Scalable Mode fault information

[Mehta, Sohil]

On Tue, 2019-09-10 at 10:08 +0200, Joerg Roedel wrote:
> > +     "Unknown", "Unknown", "Unknown", "Unknown", "Unknown",
> "Unknown", "Unknown", /* 0x49-0x4F */
> 
> Maybe add the number (0x49-0x4f) to the respecting "Unknown" fields?
> If
> we can't give a reason we should give the number for easier debugging
> in
> the future. Same for the "Unknown" fields below.

I believe a fault number is always printed in dmar_fault_do_one() even
if the reason is unknown.

DMAR: [DMA Write] Request device [00:02.0] fault addr 108a000 [fault
reason 23] Unknown

--Sohil
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Re: [PATCH] iommu/vt-d: Add Scalable Mode fault information

[joro]

On Tue, Sep 10, 2019 at 05:30:09PM +0000, Mehta, Sohil wrote:
> On Tue, 2019-09-10 at 10:08 +0200, Joerg Roedel wrote:
> > > +     "Unknown", "Unknown", "Unknown", "Unknown", "Unknown",
> > "Unknown", "Unknown", /* 0x49-0x4F */
> > 
> > Maybe add the number (0x49-0x4f) to the respecting "Unknown" fields?
> > If
> > we can't give a reason we should give the number for easier debugging
> > in
> > the future. Same for the "Unknown" fields below.
> 
> I believe a fault number is always printed in dmar_fault_do_one() even
> if the reason is unknown.
> 
> DMAR: [DMA Write] Request device [00:02.0] fault addr 108a000 [fault
> reason 23] Unknown

Right, applied the patch, thanks.
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