Re: [PATCH v5] swiotlb: Adjust SWIOTBL bounce buffer size for SEV guests.

2020-11-18 Thread Christoph Hellwig
On Wed, Nov 18, 2020 at 08:12:43PM +, Ashish Kalra wrote: > From: Ashish Kalra > > For SEV, all DMA to and from guest has to use shared > (un-encrypted) pages. SEV uses SWIOTLB to make this > happen without requiring changes to device drivers. > However, depending on workload being run, the d

Re: [PATCH v5] swiotlb: Adjust SWIOTBL bounce buffer size for SEV guests.

2020-11-18 Thread Borislav Petkov
On Wed, Nov 18, 2020 at 08:12:43PM +, Ashish Kalra wrote: > diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c > index 3511736fbc74..0f42911cea57 100644 > --- a/arch/x86/kernel/setup.c > +++ b/arch/x86/kernel/setup.c > @@ -1166,6 +1166,10 @@ void __init setup_arch(char **cmdline_p)

[PATCH v5] swiotlb: Adjust SWIOTBL bounce buffer size for SEV guests.

2020-11-18 Thread Ashish Kalra
From: Ashish Kalra For SEV, all DMA to and from guest has to use shared (un-encrypted) pages. SEV uses SWIOTLB to make this happen without requiring changes to device drivers. However, depending on workload being run, the default 64MB of SWIOTLB might not be enough and SWIOTLB may run out of buff