| Message ID | 20170822145107.6877-10-paul.durrant@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Aug 22, 2017 at 03:51:03PM +0100, Paul Durrant wrote: > This patch re-works much of the IOREQ server initialization and teardown > code: > > - The hvm_map/unmap_ioreq_gfn() functions are expanded to call through > to hvm_alloc/free_ioreq_gfn() rather than expecting them to be called > separately by outer functions. > - Several functions now test the validity of the hvm_ioreq_page gfn value > to determine whether they need to act. This means can be safely called > for the bufioreq page even when it is not used. > - hvm_add/remove_ioreq_gfn() simply return in the case of the default > IOREQ server so callers no longer need to test before calling. > - hvm_ioreq_server_setup_pages() is renamed to hvm_ioreq_server_map_pages() > to mirror the existing hvm_ioreq_server_unmap_pages(). > > All of this significantly shortens the code. > > Signed-off-by: Paul Durrant <paul.durrant@citrix.com> > --- > Cc: Jan Beulich <jbeulich@suse.com> > Cc: Andrew Cooper <andrew.cooper3@citrix.com> > --- > xen/arch/x86/hvm/ioreq.c | 181 ++++++++++++++++++----------------------------- > 1 file changed, 69 insertions(+), 112 deletions(-) > > diff --git a/xen/arch/x86/hvm/ioreq.c b/xen/arch/x86/hvm/ioreq.c > index 5737082238..edfb394c59 100644 > --- a/xen/arch/x86/hvm/ioreq.c > +++ b/xen/arch/x86/hvm/ioreq.c > @@ -181,63 +181,76 @@ bool handle_hvm_io_completion(struct vcpu *v) > return true; > } > > -static int hvm_alloc_ioreq_gfn(struct domain *d, unsigned long *gfn) > +static unsigned long hvm_alloc_ioreq_gfn(struct hvm_ioreq_server *s) gfn_t as the return type instead? I see that you are moving it, so I won't insist (I assume there's also some other refactoring involved in making this return gfn_t). I see there are also further uses of unsigned long to store gfns, I'm not going to point those out. > { > + struct domain *d = s->domain; > unsigned int i; > - int rc; > > - rc = -ENOMEM; > + ASSERT(!s->is_default); > + > for ( i = 0; i < sizeof(d->arch.hvm_domain.ioreq_gfn.mask) * 8; i++ ) > { > if ( test_and_clear_bit(i, &d->arch.hvm_domain.ioreq_gfn.mask) ) > { The braces are not strictly needed anymore, but that's a question of taste. > - *gfn = d->arch.hvm_domain.ioreq_gfn.base + i; > - rc = 0; > - break; > + return d->arch.hvm_domain.ioreq_gfn.base + i; > } > } > > - return rc; > + return gfn_x(INVALID_GFN); > } > > -static void hvm_free_ioreq_gfn(struct domain *d, unsigned long gfn) > +static void hvm_free_ioreq_gfn(struct hvm_ioreq_server *s, > + unsigned long gfn) > { > + struct domain *d = s->domain; > unsigned int i = gfn - d->arch.hvm_domain.ioreq_gfn.base; > > - if ( gfn != gfn_x(INVALID_GFN) ) > - set_bit(i, &d->arch.hvm_domain.ioreq_gfn.mask); > + ASSERT(!s->is_default); I would maybe add a gfn != gfn_x(INVALID_GFN) in the ASSERT. > + > + set_bit(i, &d->arch.hvm_domain.ioreq_gfn.mask); > } > > -static void hvm_unmap_ioreq_page(struct hvm_ioreq_server *s, bool buf) > +static void hvm_unmap_ioreq_gfn(struct hvm_ioreq_server *s, bool buf) I'm not sure if you need the buf parameter, it seems in all cases you want to unmap everything when calling hvm_unmap_ioreq_gfn? (same applies to hvm_remove_ioreq_gfn and hvm_add_ioreq_gfn) > static int hvm_ioreq_server_map_pages(struct hvm_ioreq_server *s, > - unsigned long ioreq_gfn, > - unsigned long bufioreq_gfn) > -{ > - int rc; > - > - rc = hvm_map_ioreq_page(s, false, ioreq_gfn); > - if ( rc ) > - return rc; > - > - if ( bufioreq_gfn != gfn_x(INVALID_GFN) ) > - rc = hvm_map_ioreq_page(s, true, bufioreq_gfn); > - > - if ( rc ) > - hvm_unmap_ioreq_page(s, false); > - > - return rc; > -} > - > -static int hvm_ioreq_server_setup_pages(struct hvm_ioreq_server *s, > - bool handle_bufioreq) > + bool handle_bufioreq) > { > - struct domain *d = s->domain; > - unsigned long ioreq_gfn = gfn_x(INVALID_GFN); > - unsigned long bufioreq_gfn = gfn_x(INVALID_GFN); > - int rc; > - > - if ( s->is_default ) > - { > - /* > - * The default ioreq server must handle buffered ioreqs, for > - * backwards compatibility. > - */ > - ASSERT(handle_bufioreq); > - return hvm_ioreq_server_map_pages(s, > - d->arch.hvm_domain.params[HVM_PARAM_IOREQ_PFN], > - d->arch.hvm_domain.params[HVM_PARAM_BUFIOREQ_PFN]); > - } > + int rc = -ENOMEM; No need to set rc, you are just overwriting it in the next line. Roger.
> -----Original Message----- > From: Roger Pau Monne > Sent: 24 August 2017 18:03 > To: Paul Durrant <Paul.Durrant@citrix.com> > Cc: xen-devel@lists.xenproject.org; Andrew Cooper > <Andrew.Cooper3@citrix.com>; Jan Beulich <jbeulich@suse.com> > Subject: Re: [Xen-devel] [PATCH v2 REPOST 09/12] x86/hvm/ioreq: simplify > code and use consistent naming > > On Tue, Aug 22, 2017 at 03:51:03PM +0100, Paul Durrant wrote: > > This patch re-works much of the IOREQ server initialization and teardown > > code: > > > > - The hvm_map/unmap_ioreq_gfn() functions are expanded to call > through > > to hvm_alloc/free_ioreq_gfn() rather than expecting them to be called > > separately by outer functions. > > - Several functions now test the validity of the hvm_ioreq_page gfn value > > to determine whether they need to act. This means can be safely called > > for the bufioreq page even when it is not used. > > - hvm_add/remove_ioreq_gfn() simply return in the case of the default > > IOREQ server so callers no longer need to test before calling. > > - hvm_ioreq_server_setup_pages() is renamed to > hvm_ioreq_server_map_pages() > > to mirror the existing hvm_ioreq_server_unmap_pages(). > > > > All of this significantly shortens the code. > > > > Signed-off-by: Paul Durrant <paul.durrant@citrix.com> > > --- > > Cc: Jan Beulich <jbeulich@suse.com> > > Cc: Andrew Cooper <andrew.cooper3@citrix.com> > > --- > > xen/arch/x86/hvm/ioreq.c | 181 ++++++++++++++++++---------------------- > ------- > > 1 file changed, 69 insertions(+), 112 deletions(-) > > > > diff --git a/xen/arch/x86/hvm/ioreq.c b/xen/arch/x86/hvm/ioreq.c > > index 5737082238..edfb394c59 100644 > > --- a/xen/arch/x86/hvm/ioreq.c > > +++ b/xen/arch/x86/hvm/ioreq.c > > @@ -181,63 +181,76 @@ bool handle_hvm_io_completion(struct vcpu *v) > > return true; > > } > > > > -static int hvm_alloc_ioreq_gfn(struct domain *d, unsigned long *gfn) > > +static unsigned long hvm_alloc_ioreq_gfn(struct hvm_ioreq_server *s) > > gfn_t as the return type instead? I see that you are moving it, so I > won't insist (I assume there's also some other refactoring involved in > making this return gfn_t). I see there are also further uses of > unsigned long to store gfns, I'm not going to point those out. > > > { > > + struct domain *d = s->domain; > > unsigned int i; > > - int rc; > > > > - rc = -ENOMEM; > > + ASSERT(!s->is_default); > > + > > for ( i = 0; i < sizeof(d->arch.hvm_domain.ioreq_gfn.mask) * 8; i++ ) > > { > > if ( test_and_clear_bit(i, &d->arch.hvm_domain.ioreq_gfn.mask) ) > > { > > The braces are not strictly needed anymore, but that's a question of > taste. > > > - *gfn = d->arch.hvm_domain.ioreq_gfn.base + i; > > - rc = 0; > > - break; > > + return d->arch.hvm_domain.ioreq_gfn.base + i; > > } > > } > > > > - return rc; > > + return gfn_x(INVALID_GFN); > > } > > > > -static void hvm_free_ioreq_gfn(struct domain *d, unsigned long gfn) > > +static void hvm_free_ioreq_gfn(struct hvm_ioreq_server *s, > > + unsigned long gfn) > > { > > + struct domain *d = s->domain; > > unsigned int i = gfn - d->arch.hvm_domain.ioreq_gfn.base; > > > > - if ( gfn != gfn_x(INVALID_GFN) ) > > - set_bit(i, &d->arch.hvm_domain.ioreq_gfn.mask); > > + ASSERT(!s->is_default); > > I would maybe add a gfn != gfn_x(INVALID_GFN) in the ASSERT. > > > + > > + set_bit(i, &d->arch.hvm_domain.ioreq_gfn.mask); > > } > > > > -static void hvm_unmap_ioreq_page(struct hvm_ioreq_server *s, bool > buf) > > +static void hvm_unmap_ioreq_gfn(struct hvm_ioreq_server *s, bool buf) > > I'm not sure if you need the buf parameter, it seems in all cases you > want to unmap everything when calling hvm_unmap_ioreq_gfn? (same > applies to hvm_remove_ioreq_gfn and hvm_add_ioreq_gfn) It's really just so map/unmap and add/remove mirror each other. > > > static int hvm_ioreq_server_map_pages(struct hvm_ioreq_server *s, > > - unsigned long ioreq_gfn, > > - unsigned long bufioreq_gfn) > > -{ > > - int rc; > > - > > - rc = hvm_map_ioreq_page(s, false, ioreq_gfn); > > - if ( rc ) > > - return rc; > > - > > - if ( bufioreq_gfn != gfn_x(INVALID_GFN) ) > > - rc = hvm_map_ioreq_page(s, true, bufioreq_gfn); > > - > > - if ( rc ) > > - hvm_unmap_ioreq_page(s, false); > > - > > - return rc; > > -} > > - > > -static int hvm_ioreq_server_setup_pages(struct hvm_ioreq_server *s, > > - bool handle_bufioreq) > > + bool handle_bufioreq) > > { > > - struct domain *d = s->domain; > > - unsigned long ioreq_gfn = gfn_x(INVALID_GFN); > > - unsigned long bufioreq_gfn = gfn_x(INVALID_GFN); > > - int rc; > > - > > - if ( s->is_default ) > > - { > > - /* > > - * The default ioreq server must handle buffered ioreqs, for > > - * backwards compatibility. > > - */ > > - ASSERT(handle_bufioreq); > > - return hvm_ioreq_server_map_pages(s, > > - d->arch.hvm_domain.params[HVM_PARAM_IOREQ_PFN], > > - d->arch.hvm_domain.params[HVM_PARAM_BUFIOREQ_PFN]); > > - } > > + int rc = -ENOMEM; > > No need to set rc, you are just overwriting it in the next line. > Indeed. Thanks, Paul > Roger.
diff --git a/xen/arch/x86/hvm/ioreq.c b/xen/arch/x86/hvm/ioreq.c index 5737082238..edfb394c59 100644 --- a/xen/arch/x86/hvm/ioreq.c +++ b/xen/arch/x86/hvm/ioreq.c @@ -181,63 +181,76 @@ bool handle_hvm_io_completion(struct vcpu *v) return true; } -static int hvm_alloc_ioreq_gfn(struct domain *d, unsigned long *gfn) +static unsigned long hvm_alloc_ioreq_gfn(struct hvm_ioreq_server *s) { + struct domain *d = s->domain; unsigned int i; - int rc; - rc = -ENOMEM; + ASSERT(!s->is_default); + for ( i = 0; i < sizeof(d->arch.hvm_domain.ioreq_gfn.mask) * 8; i++ ) { if ( test_and_clear_bit(i, &d->arch.hvm_domain.ioreq_gfn.mask) ) { - *gfn = d->arch.hvm_domain.ioreq_gfn.base + i; - rc = 0; - break; + return d->arch.hvm_domain.ioreq_gfn.base + i; } } - return rc; + return gfn_x(INVALID_GFN); } -static void hvm_free_ioreq_gfn(struct domain *d, unsigned long gfn) +static void hvm_free_ioreq_gfn(struct hvm_ioreq_server *s, + unsigned long gfn) { + struct domain *d = s->domain; unsigned int i = gfn - d->arch.hvm_domain.ioreq_gfn.base; - if ( gfn != gfn_x(INVALID_GFN) ) - set_bit(i, &d->arch.hvm_domain.ioreq_gfn.mask); + ASSERT(!s->is_default); + + set_bit(i, &d->arch.hvm_domain.ioreq_gfn.mask); } -static void hvm_unmap_ioreq_page(struct hvm_ioreq_server *s, bool buf) +static void hvm_unmap_ioreq_gfn(struct hvm_ioreq_server *s, bool buf) { struct hvm_ioreq_page *iorp = buf ? &s->bufioreq : &s->ioreq; + if ( iorp->gfn == gfn_x(INVALID_GFN) ) + return; + destroy_ring_for_helper(&iorp->va, iorp->page); + iorp->page = NULL; + + if ( !s->is_default ) + hvm_free_ioreq_gfn(s, iorp->gfn); + + iorp->gfn = gfn_x(INVALID_GFN); } -static int hvm_map_ioreq_page( - struct hvm_ioreq_server *s, bool buf, unsigned long gfn) +static int hvm_map_ioreq_gfn(struct hvm_ioreq_server *s, bool buf) { struct domain *d = s->domain; struct hvm_ioreq_page *iorp = buf ? &s->bufioreq : &s->ioreq; - struct page_info *page; - void *va; int rc; - if ( (rc = prepare_ring_for_helper(d, gfn, &page, &va)) ) - return rc; - - if ( (iorp->va != NULL) || d->is_dying ) - { - destroy_ring_for_helper(&va, page); + if ( d->is_dying ) return -EINVAL; - } - iorp->va = va; - iorp->page = page; - iorp->gfn = gfn; + if ( s->is_default ) + iorp->gfn = buf ? + d->arch.hvm_domain.params[HVM_PARAM_BUFIOREQ_PFN] : + d->arch.hvm_domain.params[HVM_PARAM_IOREQ_PFN]; + else + iorp->gfn = hvm_alloc_ioreq_gfn(s); + + if ( iorp->gfn == gfn_x(INVALID_GFN) ) + return -ENOMEM; - return 0; + rc = prepare_ring_for_helper(d, iorp->gfn, &iorp->page, &iorp->va); + + if ( rc ) + hvm_unmap_ioreq_gfn(s, buf); + + return rc; } bool is_ioreq_server_page(struct domain *d, const struct page_info *page) @@ -251,8 +264,7 @@ bool is_ioreq_server_page(struct domain *d, const struct page_info *page) &d->arch.hvm_domain.ioreq_server.list, list_entry ) { - if ( (s->ioreq.va && s->ioreq.page == page) || - (s->bufioreq.va && s->bufioreq.page == page) ) + if ( (s->ioreq.page == page) || (s->bufioreq.page == page) ) { found = true; break; @@ -264,20 +276,30 @@ bool is_ioreq_server_page(struct domain *d, const struct page_info *page) return found; } -static void hvm_remove_ioreq_gfn( - struct domain *d, struct hvm_ioreq_page *iorp) +static void hvm_remove_ioreq_gfn(struct hvm_ioreq_server *s, bool buf) + { + struct domain *d = s->domain; + struct hvm_ioreq_page *iorp = buf ? &s->bufioreq : &s->ioreq; + + if ( s->is_default || iorp->gfn == gfn_x(INVALID_GFN) ) + return; + if ( guest_physmap_remove_page(d, _gfn(iorp->gfn), _mfn(page_to_mfn(iorp->page)), 0) ) domain_crash(d); clear_page(iorp->va); } -static int hvm_add_ioreq_gfn( - struct domain *d, struct hvm_ioreq_page *iorp) +static int hvm_add_ioreq_gfn(struct hvm_ioreq_server *s, bool buf) { + struct domain *d = s->domain; + struct hvm_ioreq_page *iorp = buf ? &s->bufioreq : &s->ioreq; int rc; + if ( s->is_default || iorp->gfn == gfn_x(INVALID_GFN) ) + return 0; + clear_page(iorp->va); rc = guest_physmap_add_page(d, _gfn(iorp->gfn), @@ -412,78 +434,25 @@ static void hvm_ioreq_server_remove_all_vcpus(struct hvm_ioreq_server *s) } static int hvm_ioreq_server_map_pages(struct hvm_ioreq_server *s, - unsigned long ioreq_gfn, - unsigned long bufioreq_gfn) -{ - int rc; - - rc = hvm_map_ioreq_page(s, false, ioreq_gfn); - if ( rc ) - return rc; - - if ( bufioreq_gfn != gfn_x(INVALID_GFN) ) - rc = hvm_map_ioreq_page(s, true, bufioreq_gfn); - - if ( rc ) - hvm_unmap_ioreq_page(s, false); - - return rc; -} - -static int hvm_ioreq_server_setup_pages(struct hvm_ioreq_server *s, - bool handle_bufioreq) + bool handle_bufioreq) { - struct domain *d = s->domain; - unsigned long ioreq_gfn = gfn_x(INVALID_GFN); - unsigned long bufioreq_gfn = gfn_x(INVALID_GFN); - int rc; - - if ( s->is_default ) - { - /* - * The default ioreq server must handle buffered ioreqs, for - * backwards compatibility. - */ - ASSERT(handle_bufioreq); - return hvm_ioreq_server_map_pages(s, - d->arch.hvm_domain.params[HVM_PARAM_IOREQ_PFN], - d->arch.hvm_domain.params[HVM_PARAM_BUFIOREQ_PFN]); - } + int rc = -ENOMEM; - rc = hvm_alloc_ioreq_gfn(d, &ioreq_gfn); + rc = hvm_map_ioreq_gfn(s, false); if ( !rc && handle_bufioreq ) - rc = hvm_alloc_ioreq_gfn(d, &bufioreq_gfn); - - if ( !rc ) - rc = hvm_ioreq_server_map_pages(s, ioreq_gfn, bufioreq_gfn); + rc = hvm_map_ioreq_gfn(s, true); if ( rc ) - { - hvm_free_ioreq_gfn(d, ioreq_gfn); - hvm_free_ioreq_gfn(d, bufioreq_gfn); - } + hvm_unmap_ioreq_gfn(s, false); return rc; } static void hvm_ioreq_server_unmap_pages(struct hvm_ioreq_server *s) { - struct domain *d = s->domain; - bool handle_bufioreq = !!s->bufioreq.va; - - if ( handle_bufioreq ) - hvm_unmap_ioreq_page(s, true); - - hvm_unmap_ioreq_page(s, false); - - if ( !s->is_default ) - { - if ( handle_bufioreq ) - hvm_free_ioreq_gfn(d, s->bufioreq.gfn); - - hvm_free_ioreq_gfn(d, s->ioreq.gfn); - } + hvm_unmap_ioreq_gfn(s, true); + hvm_unmap_ioreq_gfn(s, false); } static void hvm_ioreq_server_free_rangesets(struct hvm_ioreq_server *s) @@ -540,22 +509,15 @@ static int hvm_ioreq_server_alloc_rangesets(struct hvm_ioreq_server *s) static void hvm_ioreq_server_enable(struct hvm_ioreq_server *s) { - struct domain *d = s->domain; struct hvm_ioreq_vcpu *sv; - bool handle_bufioreq = !!s->bufioreq.va; spin_lock(&s->lock); if ( s->enabled ) goto done; - if ( !s->is_default ) - { - hvm_remove_ioreq_gfn(d, &s->ioreq); - - if ( handle_bufioreq ) - hvm_remove_ioreq_gfn(d, &s->bufioreq); - } + hvm_remove_ioreq_gfn(s, false); + hvm_remove_ioreq_gfn(s, true); s->enabled = true; @@ -570,21 +532,13 @@ static void hvm_ioreq_server_enable(struct hvm_ioreq_server *s) static void hvm_ioreq_server_disable(struct hvm_ioreq_server *s) { - struct domain *d = s->domain; - bool handle_bufioreq = !!s->bufioreq.va; - spin_lock(&s->lock); if ( !s->enabled ) goto done; - if ( !s->is_default ) - { - if ( handle_bufioreq ) - hvm_add_ioreq_gfn(d, &s->bufioreq); - - hvm_add_ioreq_gfn(d, &s->ioreq); - } + hvm_add_ioreq_gfn(s, true); + hvm_add_ioreq_gfn(s, false); s->enabled = false; @@ -607,6 +561,9 @@ static int hvm_ioreq_server_init(struct hvm_ioreq_server *s, INIT_LIST_HEAD(&s->ioreq_vcpu_list); spin_lock_init(&s->bufioreq_lock); + s->ioreq.gfn = gfn_x(INVALID_GFN); + s->bufioreq.gfn = gfn_x(INVALID_GFN); + rc = hvm_ioreq_server_alloc_rangesets(s); if ( rc ) return rc; @@ -614,7 +571,7 @@ static int hvm_ioreq_server_init(struct hvm_ioreq_server *s, if ( bufioreq_handling == HVM_IOREQSRV_BUFIOREQ_ATOMIC ) s->bufioreq_atomic = true; - rc = hvm_ioreq_server_setup_pages( + rc = hvm_ioreq_server_map_pages( s, bufioreq_handling != HVM_IOREQSRV_BUFIOREQ_OFF); if ( rc ) goto fail_map;
This patch re-works much of the IOREQ server initialization and teardown code: - The hvm_map/unmap_ioreq_gfn() functions are expanded to call through to hvm_alloc/free_ioreq_gfn() rather than expecting them to be called separately by outer functions. - Several functions now test the validity of the hvm_ioreq_page gfn value to determine whether they need to act. This means can be safely called for the bufioreq page even when it is not used. - hvm_add/remove_ioreq_gfn() simply return in the case of the default IOREQ server so callers no longer need to test before calling. - hvm_ioreq_server_setup_pages() is renamed to hvm_ioreq_server_map_pages() to mirror the existing hvm_ioreq_server_unmap_pages(). All of this significantly shortens the code. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> --- Cc: Jan Beulich <jbeulich@suse.com> Cc: Andrew Cooper <andrew.cooper3@citrix.com> --- xen/arch/x86/hvm/ioreq.c | 181 ++++++++++++++++++----------------------------- 1 file changed, 69 insertions(+), 112 deletions(-)