Re: [PATCH 1/2] target/arm: Add cpu property to control pauth

2020-08-13 Thread Mark Rutland
On Thu, Aug 13, 2020 at 11:49:07AM +0200, Andrew Jones wrote: > On Thu, Aug 13, 2020 at 10:05:04AM +0100, Mark Rutland wrote: > > On Thu, Aug 13, 2020 at 08:03:21AM +0200, Andrew Jones wrote: > > > Thinking about this some more, maybe we don't need pauth-arch. > > > If we don't, then it simplifies

Re: [PATCH 1/2] target/arm: Add cpu property to control pauth

2020-08-13 Thread Andrew Jones
On Thu, Aug 13, 2020 at 10:05:04AM +0100, Mark Rutland wrote: > On Thu, Aug 13, 2020 at 08:03:21AM +0200, Andrew Jones wrote: > > Thinking about this some more, maybe we don't need pauth-arch. > > If we don't, then it simplifies nicely to > > > > # Default (enabled with architected algorithm) >

Re: [PATCH 1/2] target/arm: Add cpu property to control pauth

2020-08-13 Thread Mark Rutland
On Thu, Aug 13, 2020 at 08:03:21AM +0200, Andrew Jones wrote: > Thinking about this some more, maybe we don't need pauth-arch. > If we don't, then it simplifies nicely to > > # Default (enabled with architected algorithm) > -cpu max[,pauth=on][,pauth-fast=off] > > # Select pauth-fast > -cpu

Re: [PATCH 1/2] target/arm: Add cpu property to control pauth

2020-08-13 Thread Andrew Jones
On Wed, Aug 12, 2020 at 06:31:11PM +0200, Andrew Jones wrote: > On Wed, Aug 12, 2020 at 08:10:47AM -0700, Richard Henderson wrote: > > On 8/12/20 4:00 AM, Andrew Jones wrote: > > > On Tue, Aug 11, 2020 at 11:53:38PM -0700, Richard Henderson wrote: > > >> The crypto overhead of emulating pauth can

Re: [PATCH 1/2] target/arm: Add cpu property to control pauth

2020-08-12 Thread Andrew Jones
On Wed, Aug 12, 2020 at 08:10:47AM -0700, Richard Henderson wrote: > On 8/12/20 4:00 AM, Andrew Jones wrote: > > On Tue, Aug 11, 2020 at 11:53:38PM -0700, Richard Henderson wrote: > >> The crypto overhead of emulating pauth can be significant for > >> some workloads. Add an enumeration property

Re: [PATCH 1/2] target/arm: Add cpu property to control pauth

2020-08-12 Thread Richard Henderson
On 8/12/20 4:00 AM, Andrew Jones wrote: > On Tue, Aug 11, 2020 at 11:53:38PM -0700, Richard Henderson wrote: >> The crypto overhead of emulating pauth can be significant for >> some workloads. Add an enumeration property that allows the >> feature to be turned off, on with the architected

Re: [PATCH 1/2] target/arm: Add cpu property to control pauth

2020-08-12 Thread Andrew Jones
On Tue, Aug 11, 2020 at 11:53:38PM -0700, Richard Henderson wrote: > The crypto overhead of emulating pauth can be significant for > some workloads. Add an enumeration property that allows the > feature to be turned off, on with the architected algorithm, > or on with an implementation defined

[PATCH 1/2] target/arm: Add cpu property to control pauth

2020-08-12 Thread Richard Henderson
The crypto overhead of emulating pauth can be significant for some workloads. Add an enumeration property that allows the feature to be turned off, on with the architected algorithm, or on with an implementation defined algorithm. The architected algorithm is quite expensive to emulate; using