Re: [PATCH v2] arm64: Branch predictor hardening for Cavium ThunderX2

2018-01-18 Thread Jon Masters
Hi JC, Will, On 01/18/2018 06:28 PM, Jayachandran C wrote: > On Thu, Jan 18, 2018 at 01:27:15PM -0500, Jon Masters wrote: >> On 01/18/2018 12:56 PM, Jayachandran C wrote: >>> On Thu, Jan 18, 2018 at 01:53:55PM +, Will Deacon wrote: >>> I think in this case we have to choose between crashing o

Re: [PATCH v2] arm64: Branch predictor hardening for Cavium ThunderX2

2018-01-18 Thread Jayachandran C
Hi Jon, On Thu, Jan 18, 2018 at 01:27:15PM -0500, Jon Masters wrote: > On 01/18/2018 12:56 PM, Jayachandran C wrote: > > On Thu, Jan 18, 2018 at 01:53:55PM +, Will Deacon wrote: > >> Hi JC, > >> > >> On Tue, Jan 16, 2018 at 03:45:54PM -0800, Jayachandran C wrote: > >>> On Tue, Jan 16, 2018 at

Re: [PATCH v2] arm64: Branch predictor hardening for Cavium ThunderX2

2018-01-18 Thread Jon Masters
On 01/18/2018 12:56 PM, Jayachandran C wrote: > On Thu, Jan 18, 2018 at 01:53:55PM +, Will Deacon wrote: >> Hi JC, >> >> On Tue, Jan 16, 2018 at 03:45:54PM -0800, Jayachandran C wrote: >>> On Tue, Jan 16, 2018 at 04:52:53PM -0500, Jon Masters wrote: On 01/09/2018 07:47 AM, Jayachandran C w

Re: [PATCH v2] arm64: Branch predictor hardening for Cavium ThunderX2

2018-01-18 Thread Jayachandran C
On Thu, Jan 18, 2018 at 01:53:55PM +, Will Deacon wrote: > Hi JC, > > On Tue, Jan 16, 2018 at 03:45:54PM -0800, Jayachandran C wrote: > > On Tue, Jan 16, 2018 at 04:52:53PM -0500, Jon Masters wrote: > > > On 01/09/2018 07:47 AM, Jayachandran C wrote: > > > > > > > Use PSCI based mitigation fo

Re: [PATCH v2] arm64: Branch predictor hardening for Cavium ThunderX2

2018-01-18 Thread Will Deacon
Hi JC, On Tue, Jan 16, 2018 at 03:45:54PM -0800, Jayachandran C wrote: > On Tue, Jan 16, 2018 at 04:52:53PM -0500, Jon Masters wrote: > > On 01/09/2018 07:47 AM, Jayachandran C wrote: > > > > > Use PSCI based mitigation for speculative execution attacks targeting > > > the branch predictor. The a

Re: [PATCH v2] arm64: Branch predictor hardening for Cavium ThunderX2

2018-01-17 Thread Jon Masters
On 01/16/2018 06:45 PM, Jayachandran C wrote: > On Tue, Jan 16, 2018 at 04:52:53PM -0500, Jon Masters wrote: >> On 01/09/2018 07:47 AM, Jayachandran C wrote: >> >>> Use PSCI based mitigation for speculative execution attacks targeting >>> the branch predictor. The approach is similar to the one use

Re: [PATCH v2] arm64: Branch predictor hardening for Cavium ThunderX2

2018-01-16 Thread Jayachandran C
On Tue, Jan 16, 2018 at 04:52:53PM -0500, Jon Masters wrote: > On 01/09/2018 07:47 AM, Jayachandran C wrote: > > > Use PSCI based mitigation for speculative execution attacks targeting > > the branch predictor. The approach is similar to the one used for > > Cortex-A CPUs, but in case of ThunderX2

Re: [PATCH v2] arm64: Branch predictor hardening for Cavium ThunderX2

2018-01-16 Thread Jon Masters
On 01/09/2018 07:47 AM, Jayachandran C wrote: > Use PSCI based mitigation for speculative execution attacks targeting > the branch predictor. The approach is similar to the one used for > Cortex-A CPUs, but in case of ThunderX2 we add another SMC call to > test if the firmware supports the capabil

Re: [PATCH v2] arm64: Branch predictor hardening for Cavium ThunderX2

2018-01-16 Thread Jon Masters
On 01/09/2018 07:47 AM, Jayachandran C wrote: > Use PSCI based mitigation for speculative execution attacks targeting > the branch predictor. The approach is similar to the one used for > Cortex-A CPUs, but in case of ThunderX2 we add another SMC call to > test if the firmware supports the capabili