| Message ID | 20180328163630.48576-6-dgilbert@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Mar 28, 2018 at 9:36 AM, Dr. David Alan Gilbert (git) <dgilbert@redhat.com> wrote: > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com> > > When we're using the subsection we migrate both > the 'props' and 'tso_props' data; when we're not using > the subsection (to migrate to 2.11 or old machine types) we've > got to choose what to migrate in the main structure. > > If we're using the subsection migrate 'props' in the main structure. > If we're not using the subsection then migrate the last one > that changed, which gives behaviour similar to the old behaviour. > > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Acked-by: Ed Swierk <eswierk@gmail.com> > --- > hw/net/e1000.c | 18 +++++++++++++++++- > 1 file changed, 17 insertions(+), 1 deletion(-) > > diff --git a/hw/net/e1000.c b/hw/net/e1000.c > index 4e606d4b2a..13a9494a8d 100644 > --- a/hw/net/e1000.c > +++ b/hw/net/e1000.c > @@ -130,6 +130,7 @@ typedef struct E1000State_st { > #define E1000_FLAG_TSO (1 << E1000_FLAG_TSO_BIT) > uint32_t compat_flags; > bool received_tx_tso; > + bool use_tso_for_migration; > e1000x_txd_props mig_props; > } E1000State; > > @@ -622,9 +623,11 @@ process_tx_desc(E1000State *s, struct e1000_tx_desc *dp) > if (dtype == E1000_TXD_CMD_DEXT) { /* context descriptor */ > if (le32_to_cpu(xp->cmd_and_length) & E1000_TXD_CMD_TSE) { > e1000x_read_tx_ctx_descr(xp, &tp->tso_props); > + s->use_tso_for_migration = 1; > tp->tso_frames = 0; > } else { > e1000x_read_tx_ctx_descr(xp, &tp->props); > + s->use_tso_for_migration = 0; > } > return; > } else if (dtype == (E1000_TXD_CMD_DEXT | E1000_TXD_DTYP_D)) { > @@ -1366,7 +1369,20 @@ static int e1000_pre_save(void *opaque) > s->phy_reg[PHY_STATUS] |= MII_SR_AUTONEG_COMPLETE; > } > > - s->mig_props = s->tx.props; > + /* Decide which set of props to migrate in the main structure */ > + if (chkflag(TSO) || !s->use_tso_for_migration) { > + /* Either we're migrating with the extra subsection, in which > + * case the mig_props is always 'props' OR > + * we've not got the subsection, but 'props' was the last > + * updated. > + */ > + s->mig_props = s->tx.props; > + } else { > + /* We're not using the subsection, and 'tso_props' was > + * the last updated. > + */ > + s->mig_props = s->tx.tso_props; > + } > return 0; > } > > -- > 2.14.3 >
On 2018年03月29日 00:36, Dr. David Alan Gilbert (git) wrote: > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com> > > When we're using the subsection we migrate both > the 'props' and 'tso_props' data; when we're not using > the subsection (to migrate to 2.11 or old machine types) we've > got to choose what to migrate in the main structure. > > If we're using the subsection migrate 'props' in the main structure. > If we're not using the subsection then migrate the last one > that changed, which gives behaviour similar to the old behaviour. > > But only after migration. Why not simply switch back to the old behavior if migrate_tso_props if false? Thanks
* Jason Wang (jasowang@redhat.com) wrote: > > > On 2018年03月29日 00:36, Dr. David Alan Gilbert (git) wrote: > > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com> > > > > When we're using the subsection we migrate both > > the 'props' and 'tso_props' data; when we're not using > > the subsection (to migrate to 2.11 or old machine types) we've > > got to choose what to migrate in the main structure. > > > > If we're using the subsection migrate 'props' in the main structure. > > If we're not using the subsection then migrate the last one > > that changed, which gives behaviour similar to the old behaviour. > > > > > > But only after migration. Why not simply switch back to the old behavior if > migrate_tso_props if false? Because: 1) We know it's a broken behaviour so it's better not to unfix it 2) The fix doesn't change guest visible behaviour other than actually sending the right packets; so there's no reason to make the fix itself dependent on the machine type. 3) Gating the fix itself on the flag is actually more complex and would need checking the flag in lots of places that are already pretty complex, rather than what this does which is just check it in one place at migration. Dave > Thanks > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
On 2018年03月29日 16:08, Dr. David Alan Gilbert wrote: > * Jason Wang (jasowang@redhat.com) wrote: >> >> On 2018年03月29日 00:36, Dr. David Alan Gilbert (git) wrote: >>> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com> >>> >>> When we're using the subsection we migrate both >>> the 'props' and 'tso_props' data; when we're not using >>> the subsection (to migrate to 2.11 or old machine types) we've >>> got to choose what to migrate in the main structure. >>> >>> If we're using the subsection migrate 'props' in the main structure. >>> If we're not using the subsection then migrate the last one >>> that changed, which gives behaviour similar to the old behaviour. >>> >>> >> But only after migration. Why not simply switch back to the old behavior if >> migrate_tso_props if false? > Because: > 1) We know it's a broken behaviour so it's better not to unfix it > 2) The fix doesn't change guest visible behaviour other than actually > sending the right packets; so there's no reason to make the fix > itself dependent on the machine type. > 3) Gating the fix itself on the flag is actually more complex and > would need checking the flag in lots of places that are already > pretty complex, rather than what this does which is just check it > in one place at migration. It looks to me it was just something like: struct e1000x_txd_props *props = tp->cptse && chkflag(TSO) ? &tp->tso_props : &tp->props; Btw, did this patch work when: migrate A to B migrate B to C But there's no tx during B? Thanks > > Dave >> Thanks >> > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK >
* Jason Wang (jasowang@redhat.com) wrote: > > > On 2018年03月29日 16:08, Dr. David Alan Gilbert wrote: > > * Jason Wang (jasowang@redhat.com) wrote: > > > > > > On 2018年03月29日 00:36, Dr. David Alan Gilbert (git) wrote: > > > > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com> > > > > > > > > When we're using the subsection we migrate both > > > > the 'props' and 'tso_props' data; when we're not using > > > > the subsection (to migrate to 2.11 or old machine types) we've > > > > got to choose what to migrate in the main structure. > > > > > > > > If we're using the subsection migrate 'props' in the main structure. > > > > If we're not using the subsection then migrate the last one > > > > that changed, which gives behaviour similar to the old behaviour. > > > > > > > > > > > But only after migration. Why not simply switch back to the old behavior if > > > migrate_tso_props if false? > > Because: > > 1) We know it's a broken behaviour so it's better not to unfix it > > 2) The fix doesn't change guest visible behaviour other than actually > > sending the right packets; so there's no reason to make the fix > > itself dependent on the machine type. > > 3) Gating the fix itself on the flag is actually more complex and > > would need checking the flag in lots of places that are already > > pretty complex, rather than what this does which is just check it > > in one place at migration. > > It looks to me it was just something like: > > struct e1000x_txd_props *props = tp->cptse && chkflag(TSO) ? > &tp->tso_props : &tp->props; is that the only thing that would change? > Btw, did this patch work when: > > migrate A to B > migrate B to C > > But there's no tx during B? Hmm, good question; I only tried it keeping the stream alive during migration. Lets see what happens. For this code to be used we have to be running with an old machine type/property. That means A->B will have either come from 2.11 or a 2.12 with this same patch. But given patch 2 that duplicates on loading; that means A->B should end up with B having the same data in both sets of props, and thus it doesn't matter which set this patch picks. Dave > Thanks > > > > > Dave > > > Thanks > > > > > -- > > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK > > > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
On 2018年03月29日 16:44, Dr. David Alan Gilbert wrote: > * Jason Wang (jasowang@redhat.com) wrote: >> >> On 2018年03月29日 16:08, Dr. David Alan Gilbert wrote: >>> * Jason Wang (jasowang@redhat.com) wrote: >>>> On 2018年03月29日 00:36, Dr. David Alan Gilbert (git) wrote: >>>>> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com> >>>>> >>>>> When we're using the subsection we migrate both >>>>> the 'props' and 'tso_props' data; when we're not using >>>>> the subsection (to migrate to 2.11 or old machine types) we've >>>>> got to choose what to migrate in the main structure. >>>>> >>>>> If we're using the subsection migrate 'props' in the main structure. >>>>> If we're not using the subsection then migrate the last one >>>>> that changed, which gives behaviour similar to the old behaviour. >>>>> >>>>> >>>> But only after migration. Why not simply switch back to the old behavior if >>>> migrate_tso_props if false? >>> Because: >>> 1) We know it's a broken behaviour so it's better not to unfix it >>> 2) The fix doesn't change guest visible behaviour other than actually >>> sending the right packets; so there's no reason to make the fix >>> itself dependent on the machine type. >>> 3) Gating the fix itself on the flag is actually more complex and >>> would need checking the flag in lots of places that are already >>> pretty complex, rather than what this does which is just check it >>> in one place at migration. >> It looks to me it was just something like: >> >> struct e1000x_txd_props *props = tp->cptse && chkflag(TSO) ? >> &tp->tso_props : &tp->props; > is that the only thing that would change? Looks like and we can avoid using tricks like patch 4. > >> Btw, did this patch work when: >> >> migrate A to B >> migrate B to C >> >> But there's no tx during B? > Hmm, good question; I only tried it keeping the stream alive during > migration. > Lets see what happens. > > For this code to be used we have to be running with an old machine > type/property. > That means A->B will have either come from 2.11 or a 2.12 with this same > patch. > But given patch 2 that duplicates on loading; that means A->B should > end up with B having the same data in both sets of props, and > thus it doesn't matter which set this patch picks. Yes it is. I think I would agree with your idea now consider it was slightly better than using the old behavior. Thanks > > Dave > >> Thanks >> >>> Dave >>>> Thanks >>>> >>> -- >>> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK >>> > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK >
On 28/03/2018 18:36, Dr. David Alan Gilbert (git) wrote: > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com> > > When we're using the subsection we migrate both > the 'props' and 'tso_props' data; when we're not using > the subsection (to migrate to 2.11 or old machine types) we've > got to choose what to migrate in the main structure. > > If we're using the subsection migrate 'props' in the main structure. > If we're not using the subsection then migrate the last one > that changed, which gives behaviour similar to the old behaviour. > > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > --- > hw/net/e1000.c | 18 +++++++++++++++++- > 1 file changed, 17 insertions(+), 1 deletion(-) > > diff --git a/hw/net/e1000.c b/hw/net/e1000.c > index 4e606d4b2a..13a9494a8d 100644 > --- a/hw/net/e1000.c > +++ b/hw/net/e1000.c > @@ -130,6 +130,7 @@ typedef struct E1000State_st { > #define E1000_FLAG_TSO (1 << E1000_FLAG_TSO_BIT) > uint32_t compat_flags; > bool received_tx_tso; > + bool use_tso_for_migration; > e1000x_txd_props mig_props; > } E1000State; > > @@ -622,9 +623,11 @@ process_tx_desc(E1000State *s, struct e1000_tx_desc *dp) > if (dtype == E1000_TXD_CMD_DEXT) { /* context descriptor */ > if (le32_to_cpu(xp->cmd_and_length) & E1000_TXD_CMD_TSE) { > e1000x_read_tx_ctx_descr(xp, &tp->tso_props); > + s->use_tso_for_migration = 1; > tp->tso_frames = 0; > } else { > e1000x_read_tx_ctx_descr(xp, &tp->props); > + s->use_tso_for_migration = 0; > } > return; > } else if (dtype == (E1000_TXD_CMD_DEXT | E1000_TXD_DTYP_D)) { > @@ -1366,7 +1369,20 @@ static int e1000_pre_save(void *opaque) > s->phy_reg[PHY_STATUS] |= MII_SR_AUTONEG_COMPLETE; > } > > - s->mig_props = s->tx.props; > + /* Decide which set of props to migrate in the main structure */ > + if (chkflag(TSO) || !s->use_tso_for_migration) { > + /* Either we're migrating with the extra subsection, in which > + * case the mig_props is always 'props' OR > + * we've not got the subsection, but 'props' was the last > + * updated. > + */ > + s->mig_props = s->tx.props; > + } else { > + /* We're not using the subsection, and 'tso_props' was > + * the last updated. > + */ > + s->mig_props = s->tx.tso_props; > + } > return 0; > } Looks good, thanks! Paolo
diff --git a/hw/net/e1000.c b/hw/net/e1000.c index 4e606d4b2a..13a9494a8d 100644 --- a/hw/net/e1000.c +++ b/hw/net/e1000.c @@ -130,6 +130,7 @@ typedef struct E1000State_st { #define E1000_FLAG_TSO (1 << E1000_FLAG_TSO_BIT) uint32_t compat_flags; bool received_tx_tso; + bool use_tso_for_migration; e1000x_txd_props mig_props; } E1000State; @@ -622,9 +623,11 @@ process_tx_desc(E1000State *s, struct e1000_tx_desc *dp) if (dtype == E1000_TXD_CMD_DEXT) { /* context descriptor */ if (le32_to_cpu(xp->cmd_and_length) & E1000_TXD_CMD_TSE) { e1000x_read_tx_ctx_descr(xp, &tp->tso_props); + s->use_tso_for_migration = 1; tp->tso_frames = 0; } else { e1000x_read_tx_ctx_descr(xp, &tp->props); + s->use_tso_for_migration = 0; } return; } else if (dtype == (E1000_TXD_CMD_DEXT | E1000_TXD_DTYP_D)) { @@ -1366,7 +1369,20 @@ static int e1000_pre_save(void *opaque) s->phy_reg[PHY_STATUS] |= MII_SR_AUTONEG_COMPLETE; } - s->mig_props = s->tx.props; + /* Decide which set of props to migrate in the main structure */ + if (chkflag(TSO) || !s->use_tso_for_migration) { + /* Either we're migrating with the extra subsection, in which + * case the mig_props is always 'props' OR + * we've not got the subsection, but 'props' was the last + * updated. + */ + s->mig_props = s->tx.props; + } else { + /* We're not using the subsection, and 'tso_props' was + * the last updated. + */ + s->mig_props = s->tx.tso_props; + } return 0; }