Intel IOMMU: RMRRs do not necessarily have to be present on all VT-d capable platforms
PATCH 1/1 Intel IOMMU: RMRRs do not necessarily have to be present on all VT-d capable platforms
RMRRs do not necessarily have to be present on all VT-d capable platforms. The printk is just informational and does not need to be followed by an error return.
--- dmar.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)
drivers/pci/dmar.c +1 -3
@@ -317,10 +317,8 @@ int __init dmar_table_init(void)return -ENODEV ; } -if (list_empty (&dmar_rmrr_units)) { +if (list_empty (&dmar_rmrr_units)) printk(KERN_INFO PREFIX "No RMRR found\n"); -return -ENODEV ; - }return 0 ; }
Quoted 26 lines · On Tue, 1 Jul 2008 05:13:54 -0400 Yong Wang <[email protected]> wrote:
RMRRs do not necessarily have to be present on all VT-d capable platforms. The printk is just informational and does not need to be followed by an error return.
Signed-off-by Yong Y Wang <[email protected]>--- dmar.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)drivers/pci/dmar.c +1
-3@@ -317,10 +317,8 @@ int __init dmar_table_init(void)return -ENODEV ; } -if (list_empty (&dmar_rmrr_units)) { +if (list_empty (&dmar_rmrr_units)) printk(KERN_INFO PREFIX "No RMRR found\n"); -return -ENODEV ; - }return 0 ; }
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From your description I am unable to work out how important this fix is.
Is it needed in 2.6.25.x? In 2.6.26? In 2.6.27? There's no way for me to know :(
Quoted 25 lines · Andrew Morton
Quoted 23 lines · On Tue, 1 Jul 2008 05:13:54 -0400 Yong Wang <[email protected]> wrote:
RMRRs do not necessarily have to be present on all VT-d capable platforms. The printk is just informational and does not need to be followed by an error return.
Signed-off-by Yong Y Wang <[email protected]>--- dmar.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)drivers/pci/dmar.c +1
-3@@ -317,10 +317,8 @@ int __init dmar_table_init(void)return -ENODEV ; } -if (list_empty (&dmar_rmrr_units)) { +if (list_empty (&dmar_rmrr_units)) printk(KERN_INFO PREFIX "No RMRR found\n"); -return -ENODEV ; - }
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drivers/pci/dmar.c +0
-0return 0 ; }From your description I am unable to work out how important this fix is.
Is it needed in 2.6.25.x? In 2.6.26? In 2.6.27? There's no way for me to know :(
Actually this is the same as Suresh' x2apic patch 05/26. The absence of RMRRs will prevent kernel from parsing IOxAPICs without this patch and thus leaves IOxAPICs in an uninitialized state.
Quoted 29 lines · On Thu, 10 Jul 2008 19:53:26 -0400 Yong Wang <[email protected]>…
Quoted 28 lines · Andrew Morton
Quoted 25 lines · On Tue, 1 Jul 2008 05:13:54 -0400 Yong Wang <[email protected]> wrote:
RMRRs do not necessarily have to be present on all VT-d capable platforms. The printk is just informational and does not need to be followed by an error return.
Signed-off-by Yong Y Wang <[email protected]>--- dmar.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)drivers/pci/dmar.c +1
-3@@ -317,10 +317,8 @@ int __init dmar_table_init(void)return -ENODEV ; } -if (list_empty (&dmar_rmrr_units)) { +if (list_empty (&dmar_rmrr_units)) printk(KERN_INFO PREFIX "No RMRR found\n"); -return -ENODEV ; - }return 0 ; }
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From your description I am unable to work out how important this fix is.
Is it needed in 2.6.25.x? In 2.6.26? In 2.6.27? There's no way for me to know :(
Actually this is the same as Suresh' x2apic patch 05/26. The absence of RMRRs will prevent kernel from parsing IOxAPICs without this patch and thus leaves IOxAPICs in an uninitialized state.
And what runtime effect does that have?
Quoted 33 lines · Andrew Morton
Quoted 31 lines · On Thu, 10 Jul 2008 19:53:26 -0400 Yong Wang <[email protected]>…
Quoted 30 lines · Andrew Morton
Quoted 27 lines · On Tue, 1 Jul 2008 05:13:54 -0400 Yong Wang <[email protected]> wrote:
RMRRs do not necessarily have to be present on all VT-d capable platforms. The printk is just informational and does not need to be followed by an error return.
Signed-off-by Yong Y Wang <[email protected]>--- dmar.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)drivers/pci/dmar.c +1
-3@@ -317,10 +317,8 @@ int __init dmar_table_init(void)return -ENODEV ; } -if (list_empty (&dmar_rmrr_units)) { +if (list_empty (&dmar_rmrr_units)) printk(KERN_INFO PREFIX "No RMRR found\n"); -return -ENODEV ; - }return 0 ; }From your description I am unable to work out how important this fix is.
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Is it needed in 2.6.25.x? In 2.6.26? In 2.6.27? There's no way for me to know :(
Actually this is the same as Suresh' x2apic patch 05/26. The absence of RMRRs will prevent kernel from parsing IOxAPICs without this patch and thus leaves IOxAPICs in an uninitialized state.
And what runtime effect does that have?
Andrew, this is not urgent. It is now getting tracked as part of x2apic patchset. And also, this doesn't need to be backported to any kernel.
thanks
suresh