Re: [PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-17 Thread Alexander Graf
On 14.06.14 23:08, Madhavan Srinivasan wrote: This patch adds kernel side support for software breakpoint. Design is that, by using an illegal instruction, we trap to hypervisor via Emulation Assistance interrupt, where we check for the illegal instruction and accordingly we return to Host or

Re: [PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-17 Thread Benjamin Herrenschmidt
On Tue, 2014-06-17 at 10:54 +0200, Alexander Graf wrote: Also, why don't we use twi always or something else that actually is defined as illegal instruction? I would like to see this shared with book3s_32 PR. twi will be directed to the guest on HV no ? We want a real illegal because those

Re: [PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-17 Thread Alexander Graf
On 17.06.14 11:22, Benjamin Herrenschmidt wrote: On Tue, 2014-06-17 at 10:54 +0200, Alexander Graf wrote: Also, why don't we use twi always or something else that actually is defined as illegal instruction? I would like to see this shared with book3s_32 PR. twi will be directed to the guest

Re: [PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-17 Thread Benjamin Herrenschmidt
On Tue, 2014-06-17 at 11:25 +0200, Alexander Graf wrote: On 17.06.14 11:22, Benjamin Herrenschmidt wrote: On Tue, 2014-06-17 at 10:54 +0200, Alexander Graf wrote: Also, why don't we use twi always or something else that actually is defined as illegal instruction? I would like to see this

Re: [PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-17 Thread Alexander Graf
On 17.06.14 11:32, Benjamin Herrenschmidt wrote: On Tue, 2014-06-17 at 11:25 +0200, Alexander Graf wrote: On 17.06.14 11:22, Benjamin Herrenschmidt wrote: On Tue, 2014-06-17 at 10:54 +0200, Alexander Graf wrote: Also, why don't we use twi always or something else that actually is defined as

Re: [PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-17 Thread Madhavan Srinivasan
On Tuesday 17 June 2014 02:24 PM, Alexander Graf wrote: On 14.06.14 23:08, Madhavan Srinivasan wrote: This patch adds kernel side support for software breakpoint. Design is that, by using an illegal instruction, we trap to hypervisor via Emulation Assistance interrupt, where we check for the

Re: [PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-17 Thread Alexander Graf
On 17.06.14 13:07, Madhavan Srinivasan wrote: On Tuesday 17 June 2014 02:24 PM, Alexander Graf wrote: On 14.06.14 23:08, Madhavan Srinivasan wrote: This patch adds kernel side support for software breakpoint. Design is that, by using an illegal instruction, we trap to hypervisor via Emulation

Re: [PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-17 Thread Madhavan Srinivasan
On Tuesday 17 June 2014 03:02 PM, Benjamin Herrenschmidt wrote: On Tue, 2014-06-17 at 11:25 +0200, Alexander Graf wrote: On 17.06.14 11:22, Benjamin Herrenschmidt wrote: On Tue, 2014-06-17 at 10:54 +0200, Alexander Graf wrote: Also, why don't we use twi always or something else that actually

Re: [PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-17 Thread Madhavan Srinivasan
On Tuesday 17 June 2014 04:38 PM, Alexander Graf wrote: On 17.06.14 13:07, Madhavan Srinivasan wrote: On Tuesday 17 June 2014 02:24 PM, Alexander Graf wrote: On 14.06.14 23:08, Madhavan Srinivasan wrote: This patch adds kernel side support for software breakpoint. Design is that, by using

Re: [PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-17 Thread Madhavan Srinivasan
On Tuesday 17 June 2014 03:13 PM, Alexander Graf wrote: On 17.06.14 11:32, Benjamin Herrenschmidt wrote: On Tue, 2014-06-17 at 11:25 +0200, Alexander Graf wrote: On 17.06.14 11:22, Benjamin Herrenschmidt wrote: On Tue, 2014-06-17 at 10:54 +0200, Alexander Graf wrote: Also, why don't we use

Re: [PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-17 Thread Alexander Graf
On 17.06.14 13:13, Madhavan Srinivasan wrote: On Tuesday 17 June 2014 04:38 PM, Alexander Graf wrote: On 17.06.14 13:07, Madhavan Srinivasan wrote: On Tuesday 17 June 2014 02:24 PM, Alexander Graf wrote: On 14.06.14 23:08, Madhavan Srinivasan wrote: This patch adds kernel side support for

Re: [PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-17 Thread Benjamin Herrenschmidt
On Tue, 2014-06-17 at 11:25 +0200, Alexander Graf wrote: On 17.06.14 11:22, Benjamin Herrenschmidt wrote: On Tue, 2014-06-17 at 10:54 +0200, Alexander Graf wrote: Also, why don't we use twi always or something else that actually is defined as illegal instruction? I would like to see this

Re: [PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-17 Thread Alexander Graf
On 17.06.14 11:32, Benjamin Herrenschmidt wrote: On Tue, 2014-06-17 at 11:25 +0200, Alexander Graf wrote: On 17.06.14 11:22, Benjamin Herrenschmidt wrote: On Tue, 2014-06-17 at 10:54 +0200, Alexander Graf wrote: Also, why don't we use twi always or something else that actually is defined as

Re: [PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-17 Thread Madhavan Srinivasan
On Tuesday 17 June 2014 02:24 PM, Alexander Graf wrote: On 14.06.14 23:08, Madhavan Srinivasan wrote: This patch adds kernel side support for software breakpoint. Design is that, by using an illegal instruction, we trap to hypervisor via Emulation Assistance interrupt, where we check for the

Re: [PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-17 Thread Alexander Graf
On 17.06.14 13:07, Madhavan Srinivasan wrote: On Tuesday 17 June 2014 02:24 PM, Alexander Graf wrote: On 14.06.14 23:08, Madhavan Srinivasan wrote: This patch adds kernel side support for software breakpoint. Design is that, by using an illegal instruction, we trap to hypervisor via Emulation

Re: [PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-17 Thread Madhavan Srinivasan
On Tuesday 17 June 2014 03:02 PM, Benjamin Herrenschmidt wrote: On Tue, 2014-06-17 at 11:25 +0200, Alexander Graf wrote: On 17.06.14 11:22, Benjamin Herrenschmidt wrote: On Tue, 2014-06-17 at 10:54 +0200, Alexander Graf wrote: Also, why don't we use twi always or something else that actually

Re: [PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-17 Thread Madhavan Srinivasan
On Tuesday 17 June 2014 03:13 PM, Alexander Graf wrote: On 17.06.14 11:32, Benjamin Herrenschmidt wrote: On Tue, 2014-06-17 at 11:25 +0200, Alexander Graf wrote: On 17.06.14 11:22, Benjamin Herrenschmidt wrote: On Tue, 2014-06-17 at 10:54 +0200, Alexander Graf wrote: Also, why don't we use

Re: [PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-17 Thread Madhavan Srinivasan
On Tuesday 17 June 2014 04:38 PM, Alexander Graf wrote: On 17.06.14 13:07, Madhavan Srinivasan wrote: On Tuesday 17 June 2014 02:24 PM, Alexander Graf wrote: On 14.06.14 23:08, Madhavan Srinivasan wrote: This patch adds kernel side support for software breakpoint. Design is that, by using

Re: [PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-17 Thread Alexander Graf
On 17.06.14 13:20, Madhavan Srinivasan wrote: On Tuesday 17 June 2014 03:13 PM, Alexander Graf wrote: On 17.06.14 11:32, Benjamin Herrenschmidt wrote: On Tue, 2014-06-17 at 11:25 +0200, Alexander Graf wrote: On 17.06.14 11:22, Benjamin Herrenschmidt wrote: On Tue, 2014-06-17 at 10:54 +0200,

Re: [PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-17 Thread Alexander Graf
On 17.06.14 13:13, Madhavan Srinivasan wrote: On Tuesday 17 June 2014 04:38 PM, Alexander Graf wrote: On 17.06.14 13:07, Madhavan Srinivasan wrote: On Tuesday 17 June 2014 02:24 PM, Alexander Graf wrote: On 14.06.14 23:08, Madhavan Srinivasan wrote: This patch adds kernel side support for

[PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-14 Thread Madhavan Srinivasan
This patch adds kernel side support for software breakpoint. Design is that, by using an illegal instruction, we trap to hypervisor via Emulation Assistance interrupt, where we check for the illegal instruction and accordingly we return to Host or Guest. Patch mandates use of abs instruction

[PATCH] powerpc/kvm: support to handle sw breakpoint

2014-06-14 Thread Madhavan Srinivasan
This patch adds kernel side support for software breakpoint. Design is that, by using an illegal instruction, we trap to hypervisor via Emulation Assistance interrupt, where we check for the illegal instruction and accordingly we return to Host or Guest. Patch mandates use of abs instruction