* [PATCH V2 1/2] xen/arm: mm: remove unnecessary tlb flush in setup_pagetables
@ 2016-05-12 2:01 Peng Fan
2016-05-12 2:01 ` [PATCH V2 2/2] xen/arm: mm: clean up code " Peng Fan
2016-05-12 10:50 ` [PATCH V2 1/2] xen/arm: mm: remove unnecessary tlb flush " Julien Grall
0 siblings, 2 replies; 4+ messages in thread
From: Peng Fan @ 2016-05-12 2:01 UTC (permalink / raw)
To: xen-devel, julien.grall, sstabellini; +Cc: van.freenix
CPU0 is using the boot pages table before relocating xen and
xen_second is not part of them. So, no need to flush the TLB
when filling xen_second.
Signed-off-by: Peng Fan <van.freenix@gmail.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Julien Grall <julien.grall@arm.com>
---
V2:
Following Julien's comments:
split the V1 patch into two patches. This patch only remove tlb flush.
refine commit log
xen/arch/arm/mm.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index 94ea054..addd699 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -447,7 +447,6 @@ void __init setup_pagetables(unsigned long boot_phys_offset, paddr_t xen_paddr)
dest_va = BOOT_RELOC_VIRT_START;
pte = mfn_to_xen_entry(xen_paddr >> PAGE_SHIFT, WRITEALLOC);
write_pte(xen_second + second_table_offset(dest_va), pte);
- flush_xen_data_tlb_range_va_local(dest_va, SECOND_SIZE);
/* Calculate virt-to-phys offset for the new location */
phys_offset = xen_paddr - (unsigned long) _start;
--
2.6.2
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^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH V2 2/2] xen/arm: mm: clean up code in setup_pagetables
2016-05-12 2:01 [PATCH V2 1/2] xen/arm: mm: remove unnecessary tlb flush in setup_pagetables Peng Fan
@ 2016-05-12 2:01 ` Peng Fan
2016-05-12 10:59 ` Julien Grall
2016-05-12 10:50 ` [PATCH V2 1/2] xen/arm: mm: remove unnecessary tlb flush " Julien Grall
1 sibling, 1 reply; 4+ messages in thread
From: Peng Fan @ 2016-05-12 2:01 UTC (permalink / raw)
To: xen-devel, julien.grall, sstabellini; +Cc: van.freenix
In setup_pagetables, need to map BOOT_RELOC_VIRT_START
in xen_second and boot_second, so we can merge the two
pieces code into one code block.
Also no need to use write_pte when map BOOT_RELOC_VIRT_START
in xen_second, because CPU0 is using boot page tables now.
Signed-off-by: Peng Fan <van.freenix@gmail.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Julien Grall <julien.grall@arm.com>
---
V2:
Follow Julien's comments:
split the V1 patch into two patches, this patch is the code movement part.
xen/arch/arm/mm.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index addd699..0a4f845 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -443,11 +443,6 @@ void __init setup_pagetables(unsigned long boot_phys_offset, paddr_t xen_paddr)
lpae_t pte, *p;
int i;
- /* Map the destination in the boot misc area. */
- dest_va = BOOT_RELOC_VIRT_START;
- pte = mfn_to_xen_entry(xen_paddr >> PAGE_SHIFT, WRITEALLOC);
- write_pte(xen_second + second_table_offset(dest_va), pte);
-
/* Calculate virt-to-phys offset for the new location */
phys_offset = xen_paddr - (unsigned long) _start;
@@ -494,9 +489,12 @@ void __init setup_pagetables(unsigned long boot_phys_offset, paddr_t xen_paddr)
pte = boot_second[second_table_offset(BOOT_FDT_VIRT_START)];
xen_second[second_table_offset(BOOT_FDT_VIRT_START)] = pte;
- /* Map the destination in the boot misc area. */
+ /* ... Boot Misc area for xen relocation */
dest_va = BOOT_RELOC_VIRT_START;
pte = mfn_to_xen_entry(xen_paddr >> PAGE_SHIFT, WRITEALLOC);
+ /* Map the destination in xen_second. */
+ xen_second[second_table_offset(dest_va)] = pte;
+ /* Map the destination in boot_second. */
write_pte(boot_second + second_table_offset(dest_va), pte);
flush_xen_data_tlb_range_va_local(dest_va, SECOND_SIZE);
#ifdef CONFIG_ARM_64
--
2.6.2
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^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH V2 1/2] xen/arm: mm: remove unnecessary tlb flush in setup_pagetables
2016-05-12 2:01 [PATCH V2 1/2] xen/arm: mm: remove unnecessary tlb flush in setup_pagetables Peng Fan
2016-05-12 2:01 ` [PATCH V2 2/2] xen/arm: mm: clean up code " Peng Fan
@ 2016-05-12 10:50 ` Julien Grall
1 sibling, 0 replies; 4+ messages in thread
From: Julien Grall @ 2016-05-12 10:50 UTC (permalink / raw)
To: Peng Fan, xen-devel, sstabellini
Hi Peng,
On 12/05/16 03:01, Peng Fan wrote:
> CPU0 is using the boot pages table before relocating xen and
> xen_second is not part of them. So, no need to flush the TLB
> when filling xen_second.
>
> Signed-off-by: Peng Fan <van.freenix@gmail.com>
> Cc: Stefano Stabellini <sstabellini@kernel.org>
> Cc: Julien Grall <julien.grall@arm.com>
This will be Xen 4.8 material:
Reviewed-by: Julien Grall <julien.grall@arm.com>
Regards,
--
Julien Grall
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH V2 2/2] xen/arm: mm: clean up code in setup_pagetables
2016-05-12 2:01 ` [PATCH V2 2/2] xen/arm: mm: clean up code " Peng Fan
@ 2016-05-12 10:59 ` Julien Grall
0 siblings, 0 replies; 4+ messages in thread
From: Julien Grall @ 2016-05-12 10:59 UTC (permalink / raw)
To: Peng Fan, xen-devel, sstabellini
Hi Peng,
Hi Peng,
On 12/05/16 03:01, Peng Fan wrote:
> In setup_pagetables, need to map BOOT_RELOC_VIRT_START
> in xen_second and boot_second, so we can merge the two
> pieces code into one code block.
There is a missing subject for "need". I would say:
"The base of address for the relocated xen needs to be mapped at the
same virtual address (BOOT_RELOC_VIRT_START) in both the boot and
runtime page tables. So we can merge the two pieces of code into on code
block."
>
> Also no need to use write_pte when map BOOT_RELOC_VIRT_START
> in xen_second, because CPU0 is using boot page tables now.
>
> Signed-off-by: Peng Fan <van.freenix@gmail.com>
> Cc: Stefano Stabellini <sstabellini@kernel.org>
> Cc: Julien Grall <julien.grall@arm.com>
> ---
>
> V2:
> Follow Julien's comments:
> split the V1 patch into two patches, this patch is the code movement part.
>
> xen/arch/arm/mm.c | 10 ++++------
> 1 file changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
> index addd699..0a4f845 100644
> --- a/xen/arch/arm/mm.c
> +++ b/xen/arch/arm/mm.c
> @@ -443,11 +443,6 @@ void __init setup_pagetables(unsigned long boot_phys_offset, paddr_t xen_paddr)
> lpae_t pte, *p;
> int i;
>
> - /* Map the destination in the boot misc area. */
> - dest_va = BOOT_RELOC_VIRT_START;
> - pte = mfn_to_xen_entry(xen_paddr >> PAGE_SHIFT, WRITEALLOC);
> - write_pte(xen_second + second_table_offset(dest_va), pte);
> -
> /* Calculate virt-to-phys offset for the new location */
> phys_offset = xen_paddr - (unsigned long) _start;
>
> @@ -494,9 +489,12 @@ void __init setup_pagetables(unsigned long boot_phys_offset, paddr_t xen_paddr)
> pte = boot_second[second_table_offset(BOOT_FDT_VIRT_START)];
> xen_second[second_table_offset(BOOT_FDT_VIRT_START)] = pte;
>
> - /* Map the destination in the boot misc area. */
> + /* ... Boot Misc area for xen relocation */
> dest_va = BOOT_RELOC_VIRT_START;
> pte = mfn_to_xen_entry(xen_paddr >> PAGE_SHIFT, WRITEALLOC);
> + /* Map the destination in xen_second. */
> + xen_second[second_table_offset(dest_va)] = pte;
> + /* Map the destination in boot_second. */
> write_pte(boot_second + second_table_offset(dest_va), pte);
> flush_xen_data_tlb_range_va_local(dest_va, SECOND_SIZE);
> #ifdef CONFIG_ARM_64
>
Regards,
--
Julien Grall
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http://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 4+ messages in thread
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2016-05-12 2:01 [PATCH V2 1/2] xen/arm: mm: remove unnecessary tlb flush in setup_pagetables Peng Fan
2016-05-12 2:01 ` [PATCH V2 2/2] xen/arm: mm: clean up code " Peng Fan
2016-05-12 10:59 ` Julien Grall
2016-05-12 10:50 ` [PATCH V2 1/2] xen/arm: mm: remove unnecessary tlb flush " Julien Grall
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