Re: [PATCH 1/4] vhost: Re-enable vrings after setting features

2023-04-13 Thread Hanna Czenczek
On 13.04.23 13:03, Stefan Hajnoczi wrote: On Tue, 11 Apr 2023 at 11:05, Hanna Czenczek wrote: If the back-end supports the VHOST_USER_F_PROTOCOL_FEATURES feature, setting the vhost features will set this feature, too. Doing so disables all vrings, which may not be intended. For example, enabl

Re: [PATCH 1/4] vhost: Re-enable vrings after setting features

2023-04-13 Thread Michael S. Tsirkin
On Thu, Apr 13, 2023 at 05:24:36PM +0300, Anton Kuchin wrote: > But is there a valid use-case for logging some dirty memory but not all? > I can't understand if this is a feature or a just flaw in specification. IRC the use-case originally conceived was for shadow VQs. If you use shadow VQs the V

Re: [PATCH 1/4] vhost: Re-enable vrings after setting features

2023-04-13 Thread Anton Kuchin
On 13/04/2023 14:03, Stefan Hajnoczi wrote: On Thu, 13 Apr 2023 at 04:20, Hanna Czenczek wrote: On 12.04.23 22:51, Stefan Hajnoczi wrote: On Tue, Apr 11, 2023 at 05:05:12PM +0200, Hanna Czenczek wrote: If the back-end supports the VHOST_USER_F_PROTOCOL_FEATURES feature, setting the vhost feat

Re: [PATCH 1/4] vhost: Re-enable vrings after setting features

2023-04-13 Thread Michael S. Tsirkin
On Tue, Apr 11, 2023 at 05:05:12PM +0200, Hanna Czenczek wrote: > If the back-end supports the VHOST_USER_F_PROTOCOL_FEATURES feature, > setting the vhost features will set this feature, too. Doing so > disables all vrings, which may not be intended. Hmm not sure I understand: why does it disable

Re: [PATCH 1/4] vhost: Re-enable vrings after setting features

2023-04-13 Thread Stefan Hajnoczi
On Tue, 11 Apr 2023 at 11:05, Hanna Czenczek wrote: > > If the back-end supports the VHOST_USER_F_PROTOCOL_FEATURES feature, > setting the vhost features will set this feature, too. Doing so > disables all vrings, which may not be intended. > > For example, enabling or disabling logging during mi

Re: [PATCH 1/4] vhost: Re-enable vrings after setting features

2023-04-13 Thread Stefan Hajnoczi
On Thu, 13 Apr 2023 at 04:20, Hanna Czenczek wrote: > > On 12.04.23 22:51, Stefan Hajnoczi wrote: > > On Tue, Apr 11, 2023 at 05:05:12PM +0200, Hanna Czenczek wrote: > >> If the back-end supports the VHOST_USER_F_PROTOCOL_FEATURES feature, > >> setting the vhost features will set this feature, too

Re: [PATCH 1/4] vhost: Re-enable vrings after setting features

2023-04-13 Thread Hanna Czenczek
On 12.04.23 22:51, Stefan Hajnoczi wrote: On Tue, Apr 11, 2023 at 05:05:12PM +0200, Hanna Czenczek wrote: If the back-end supports the VHOST_USER_F_PROTOCOL_FEATURES feature, setting the vhost features will set this feature, too. Doing so disables all vrings, which may not be intended. For exa

Re: [PATCH 1/4] vhost: Re-enable vrings after setting features

2023-04-13 Thread Maxime Coquelin
On 4/12/23 22:51, Stefan Hajnoczi wrote: On Tue, Apr 11, 2023 at 05:05:12PM +0200, Hanna Czenczek wrote: If the back-end supports the VHOST_USER_F_PROTOCOL_FEATURES feature, setting the vhost features will set this feature, too. Doing so disables all vrings, which may not be intended. For e

Re: [PATCH 1/4] vhost: Re-enable vrings after setting features

2023-04-12 Thread Stefan Hajnoczi
On Tue, Apr 11, 2023 at 05:05:12PM +0200, Hanna Czenczek wrote: > If the back-end supports the VHOST_USER_F_PROTOCOL_FEATURES feature, > setting the vhost features will set this feature, too. Doing so > disables all vrings, which may not be intended. > > For example, enabling or disabling logging

Re: [PATCH 1/4] vhost: Re-enable vrings after setting features

2023-04-12 Thread Hanna Czenczek
On 12.04.23 12:55, German Maglione wrote: On Tue, Apr 11, 2023 at 5:05 PM Hanna Czenczek wrote: If the back-end supports the VHOST_USER_F_PROTOCOL_FEATURES feature, setting the vhost features will set this feature, too. Doing so disables all vrings, which may not be intended. For example, ena

Re: [PATCH 1/4] vhost: Re-enable vrings after setting features

2023-04-12 Thread German Maglione
On Tue, Apr 11, 2023 at 5:05 PM Hanna Czenczek wrote: > > If the back-end supports the VHOST_USER_F_PROTOCOL_FEATURES feature, > setting the vhost features will set this feature, too. Doing so > disables all vrings, which may not be intended. > > For example, enabling or disabling logging during

[PATCH 1/4] vhost: Re-enable vrings after setting features

2023-04-11 Thread Hanna Czenczek
If the back-end supports the VHOST_USER_F_PROTOCOL_FEATURES feature, setting the vhost features will set this feature, too. Doing so disables all vrings, which may not be intended. For example, enabling or disabling logging during migration requires setting those features (to set or unset VHOST_F