On 13.06.19 16:23, Konrad Rzeszutek Wilk wrote:
On Wed, Jun 05, 2019 at 04:24:06PM +0200, Juergen Gross wrote:
On 05.06.19 16:13, Konrad Rzeszutek Wilk wrote:
On Tue, Jun 04, 2019 at 03:41:40PM -0400, Boris Ostrovsky wrote:
On 6/4/19 12:51 PM, Stefano Stabellini wrote:
On Mon, 3 Jun 2019, Boris Ostrovsky wrote:
On 6/3/19 2:25 PM, Stefano Stabellini wrote:
On Tue, 28 May 2019, Boris Ostrovsky wrote:
On 5/28/19 6:48 PM, Stefano Stabellini wrote:
From: Stefano Stabellini <stefa...@xilinx.com>
On arm64 swiotlb is often (not always) already initialized by mem_init.
We don't want to initialize it twice, which would trigger a second
memory allocation. Moreover, the second memory pool is typically made of
high pages and ends up replacing the original memory pool of low pages.
As a side effect of this change, it is possible to have low pages in
swiotlb-xen on arm64.
Signed-off-by: Stefano Stabellini <stefa...@xilinx.com>
Has this been tested on x86?
Yes, I managed to test it using QEMU. There are no effects on x86, as
the check io_tlb_start != 0 returns false.
I wonder though whether this is always the case. When we are called
from pci_xen_swiotlb_init_late() for example.
In that case, pci_xen_swiotlb_init_late() is called by
pcifront_connect_and_init_dma, which does:
if (!err && !swiotlb_nr_tbl()) {
err = pci_xen_swiotlb_init_late();
if (err)
dev_err(&pdev->xdev->dev, "Could not setup SWIOTLB!\n");
}
pci_xen_swiotlb_init_late() is only called when swiotlb_nr_tbl() returns
0. If swiotlb_nr_tbl() returns 0, certainly the swiotlb has not been
allocated yet, and the io_tlb_start != 0 check at the beginning of
xen_swiotlb_init will also fail. The code will take the normal
route, same as today. In short, there should be no effects on x86.
OK, thanks.
Reviewed-by: Boris Ostrovsky <boris.ostrov...@oracle.com>
Pushed in devel/for-linus-5.2 and will eventually move it to stable and push to
Linus next-week.
Are there any other patches I should pick up?
I think at least the first two patches from my series:
https://patchew.org/Xen/20190529090407.1225-1-jgr...@suse.com/
are ready to go in.
#2 patch says:
"> To be symmetric with setting the flag only after having made the
region
> contiguous, and to avoid (perhaps just theoretical) races, wouldn't
it be
> better to clear the flag before calling
xen_destroy_contiguous_region()?
> Even better would be a TestAndClear...() operation.
I like that idea.
"
?
I was hoping for a clarification regarding the Xen specific page flag
names before posting V3.
As Christoph didn't react when I posted possible solutions I think I'll
just modify patch 3 according to Jan's comment and post V3.
Juergen
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