Re: [PATCH] intel_iommu: Take the bql before registering a new address space

[Philippe Mathieu-Daudé]

On 15/4/25 13:51, Paolo Bonzini wrote:

On Tue, Apr 15, 2025 at 1:51 PM CLEMENT MATHIEU--DRIF
<clement.mathieu--d...@eviden.com> wrote:

On 15/04/2025 11:30 am, Paolo Bonzini wrote:

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On 4/15/25 08:18, CLEMENT MATHIEU--DRIF wrote:

Address space creation might end up being called without holding the
bql as it is exposed through the IOMMU ops.

Signed-off-by: Clement Mathieu--Drif <clement.mathieu--d...@eviden.com>

Please use a separate lock instead of the BQL.

Hi Paolo,

We need this particular lock because some of the functions we call
require the bql to be held.

What functions do you need?

Is it a problem?

It depends on the function. :)

memory_region_set_enabled()
  -> memory_region_transaction_begin()
     -> assert(bql_locked())