From: "Jan Beulich" <JBeulich@suse.com>
To: Santosh Jodh <santosh.jodh@citrix.com>
Cc: wei.wang2@amd.com, tim@xen.org, xiantao.zhang@intel.com,
xen-devel <xen-devel@lists.xen.org>
Subject: Re: [PATCH] dump_p2m_table: For IOMMU
Date: Mon, 13 Aug 2012 09:59:14 +0100 [thread overview]
Message-ID: <5028DE020200007800094662@nat28.tlf.novell.com> (raw)
In-Reply-To: <9c7609a4fbc117b1600f.1344626094@REDBLD-XS.ad.xensource.com>
>>> On 10.08.12 at 21:14, Santosh Jodh <santosh.jodh@citrix.com> wrote:
> --- a/xen/drivers/passthrough/amd/pci_amd_iommu.c Tue Aug 07 18:37:31 2012 +0100
> +++ b/xen/drivers/passthrough/amd/pci_amd_iommu.c Fri Aug 10 08:19:58 2012 -0700
> @@ -512,6 +513,80 @@ static int amd_iommu_group_id(u16 seg, u
>
> #include <asm/io_apic.h>
>
> +static void amd_dump_p2m_table_level(struct page_info* pg, int level,
> + paddr_t gpa, int indent)
> +{
> + paddr_t address;
> + void *table_vaddr, *pde;
> + paddr_t next_table_maddr;
> + int index, next_level, present;
> + u32 *entry;
> +
> + if ( level < 1 )
> + return;
> +
> + table_vaddr = __map_domain_page(pg);
> + if ( table_vaddr == NULL )
> + {
> + printk("Failed to map IOMMU domain page %"PRIpaddr"\n",
> + page_to_maddr(pg));
> + return;
> + }
> +
> + for ( index = 0; index < PTE_PER_TABLE_SIZE; index++ )
> + {
> + if ( !(index % 2) )
> + process_pending_softirqs();
> +
> + pde = table_vaddr + (index * IOMMU_PAGE_TABLE_ENTRY_SIZE);
> + next_table_maddr = amd_iommu_get_next_table_from_pte(pde);
> + entry = (u32*)pde;
> +
> + present = get_field_from_reg_u32(entry[0],
> + IOMMU_PDE_PRESENT_MASK,
> + IOMMU_PDE_PRESENT_SHIFT);
> +
> + if ( !present )
> + continue;
> +
> + next_level = get_field_from_reg_u32(entry[0],
> + IOMMU_PDE_NEXT_LEVEL_MASK,
> + IOMMU_PDE_NEXT_LEVEL_SHIFT);
> +
> + address = gpa + amd_offset_level_address(index, level);
> + if ( (next_table_maddr != 0) && (next_level != 0) )
Why do you do this differently than for VT-d here? There
you don't check next_table_maddr (and I see no reason you
would need to). Oh, I see, there's a similar check in a different
place there. But this needs to be functionally similar here then.
Specifically, ...
> + {
> + amd_dump_p2m_table_level(
> + maddr_to_page(next_table_maddr), level - 1,
> + address, indent + 1);
> + }
> + else
... you'd get into the else's body if next_table_maddr was zero,
which is wrong afaict. So I think flow like
if ( next_level )
print
else if ( next_table_maddr )
recurse
would be the preferable way to go if you feel that these zero
checks are necessary (and if you do then, because this being
the case is really a bug, this shouldn't go through silently).
> + {
> + int i;
> +
> + for ( i = 0; i < indent; i++ )
> + printk(" ");
printk("%*s...", indent, "", ...);
> +
> + printk("gfn: %08lx mfn: %08lx\n",
> + (unsigned long)PFN_DOWN(address),
> + (unsigned long)PFN_DOWN(next_table_maddr));
> + }
> + }
> +
> + unmap_domain_page(table_vaddr);
> +}
>...
> --- a/xen/drivers/passthrough/vtd/iommu.c Tue Aug 07 18:37:31 2012 +0100
> +++ b/xen/drivers/passthrough/vtd/iommu.c Fri Aug 10 08:19:58 2012 -0700
> @@ -2365,6 +2366,71 @@ static void vtd_resume(void)
> }
> }
>
> +static void vtd_dump_p2m_table_level(paddr_t pt_maddr, int level, paddr_t gpa,
> + int indent)
> +{
> + paddr_t address;
> + int i;
> + struct dma_pte *pt_vaddr, *pte;
> + int next_level;
> +
> + if ( pt_maddr == 0 )
> + return;
> +
> + pt_vaddr = map_vtd_domain_page(pt_maddr);
> + if ( pt_vaddr == NULL )
> + {
> + printk("Failed to map VT-D domain page %"PRIpaddr"\n", pt_maddr);
> + return;
> + }
> +
> + next_level = level - 1;
> + for ( i = 0; i < PTE_NUM; i++ )
> + {
> + if ( !(i % 2) )
> + process_pending_softirqs();
> +
> + pte = &pt_vaddr[i];
> + if ( !dma_pte_present(*pte) )
> + continue;
> +
> + address = gpa + offset_level_address(i, level);
> + if ( next_level >= 1 )
> + {
> + vtd_dump_p2m_table_level(dma_pte_addr(*pte), next_level,
> + address, indent + 1);
> + }
> + else
> + {
> + int j;
> +
> + for ( j = 0; j < indent; j++ )
> + printk(" ");
See above.
Jan
> +
> + printk("gfn: %08lx mfn: %08lx super=%d rd=%d wr=%d\n",
> + (unsigned long)(address >> PAGE_SHIFT_4K),
> + (unsigned long)(pte->val >> PAGE_SHIFT_4K),
> + dma_pte_superpage(*pte)? 1 : 0,
> + dma_pte_read(*pte)? 1 : 0,
> + dma_pte_write(*pte)? 1 : 0);
> + }
> + }
> +
> + unmap_vtd_domain_page(pt_vaddr);
> +}
next prev parent reply other threads:[~2012-08-13 8:59 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-10 19:14 [PATCH] dump_p2m_table: For IOMMU Santosh Jodh
2012-08-13 8:59 ` Jan Beulich [this message]
2012-08-14 19:34 ` Santosh Jodh
2012-08-13 10:31 ` Wei Wang
-- strict thread matches above, loose matches on Subject: below --
2012-08-10 1:43 Santosh Jodh
2012-08-10 7:49 ` Jan Beulich
2012-08-10 12:31 ` Wei Wang
2012-08-10 13:02 ` Jan Beulich
2012-08-10 15:02 ` Santosh Jodh
2012-08-08 17:17 Santosh Jodh
2012-08-09 7:26 ` Jan Beulich
2012-08-10 1:41 ` Santosh Jodh
2012-08-10 10:50 ` Wei Wang
2012-08-10 12:52 ` Jan Beulich
2012-08-10 13:41 ` Wei Wang
2012-08-10 14:24 ` Jan Beulich
2012-08-08 15:56 Santosh Jodh
2012-08-08 16:21 ` Jan Beulich
2012-08-08 17:17 ` Santosh Jodh
2012-08-07 14:49 Santosh Jodh
2012-08-07 15:52 ` Jan Beulich
2012-08-07 16:16 ` Santosh Jodh
2012-08-08 7:31 ` Jan Beulich
2012-08-08 15:32 ` Santosh Jodh
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