On 27.11.2023 15:57, Boris Ostrovsky wrote:
On 11/24/23 2:48 AM, Juergen Gross wrote:
Today the percpu struct vcpu_info is allocated via DEFINE_PER_CPU(),
meaning that it could cross a page boundary. In this case registering
it with the hypervisor will fail, resulting in a panic().
This can easily be fixed by using DEFINE_PER_CPU_ALIGNED() instead,
as struct vcpu_info is guaranteed to have a size of 64 bytes, matching
the cache line size of x86 64-bit processors (Xen doesn't support
32-bit processors).
Fixes: 5ead97c84fa7 ("xen: Core Xen implementation")
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
although I am not sure in usefulness of BUILD_BUG_ON --- 64 bytes is part of ABI and hypervisor already has its own BUILD_BUG_ON for this.
I understood the check to guard against SMP_CACHE_BYTES < 64.
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