| Message ID | 20171017132432.24093-7-paul.durrant@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On 17/10/17 14:24, Paul Durrant wrote: > diff --git a/xen/common/memory.c b/xen/common/memory.c > index cdd2e030cf..b27a71c4f1 100644 > --- a/xen/common/memory.c > +++ b/xen/common/memory.c > @@ -1011,6 +1011,11 @@ static int acquire_resource( > > switch ( xmar.type ) > { > + case XENMEM_resource_ioreq_server: > + rc = xenmem_acquire_ioreq_server(d, xmar.id, xmar.frame, > + xmar.nr_frames, mfn_list); > + break; I fully appreciate you are not able to test on x86. However, I would have expected you to at least build test it. For instance, here you introduced this function on x86, call in common code but does not introduce it on Arm. Although, I don't think we should introduce it for Arm. Instead we should provide arch helpers as we do for other memory operations. Cheers,
> -----Original Message----- > From: Julien Grall [mailto:julien.grall@linaro.org] > Sent: 19 October 2017 13:31 > To: Paul Durrant <Paul.Durrant@citrix.com>; xen-devel@lists.xenproject.org > Cc: Stefano Stabellini <sstabellini@kernel.org>; Wei Liu > <wei.liu2@citrix.com>; Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>; > George Dunlap <George.Dunlap@citrix.com>; Andrew Cooper > <Andrew.Cooper3@citrix.com>; Ian Jackson <Ian.Jackson@citrix.com>; Tim > (Xen.org) <tim@xen.org>; Jan Beulich <jbeulich@suse.com> > Subject: Re: [Xen-devel] [PATCH v12 06/11] x86/hvm/ioreq: add a new > mappable resource type... > > Hi, > > On 17/10/17 14:24, Paul Durrant wrote: > > diff --git a/xen/common/memory.c b/xen/common/memory.c > > index cdd2e030cf..b27a71c4f1 100644 > > --- a/xen/common/memory.c > > +++ b/xen/common/memory.c > > @@ -1011,6 +1011,11 @@ static int acquire_resource( > > > > switch ( xmar.type ) > > { > > + case XENMEM_resource_ioreq_server: > > + rc = xenmem_acquire_ioreq_server(d, xmar.id, xmar.frame, > > + xmar.nr_frames, mfn_list); > > + break; > > I fully appreciate you are not able to test on x86. However, I would > have expected you to at least build test it. > I don't actually know how to set up cross-compilation, which is why I'd originally #ifdef-ed this. > For instance, here you introduced this function on x86, call in common > code but does not introduce it on Arm. > > Although, I don't think we should introduce it for Arm. Instead we > should provide arch helpers as we do for other memory operations. > That would be cleaner in this case. Paul > Cheers, > > -- > Julien Grall
Hi Paul, On 10/19/2017 01:58 PM, Paul Durrant wrote: >> -----Original Message----- >> From: Julien Grall [mailto:julien.grall@linaro.org] >> Sent: 19 October 2017 13:31 >> To: Paul Durrant <Paul.Durrant@citrix.com>; xen-devel@lists.xenproject.org >> Cc: Stefano Stabellini <sstabellini@kernel.org>; Wei Liu >> <wei.liu2@citrix.com>; Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>; >> George Dunlap <George.Dunlap@citrix.com>; Andrew Cooper >> <Andrew.Cooper3@citrix.com>; Ian Jackson <Ian.Jackson@citrix.com>; Tim >> (Xen.org) <tim@xen.org>; Jan Beulich <jbeulich@suse.com> >> Subject: Re: [Xen-devel] [PATCH v12 06/11] x86/hvm/ioreq: add a new >> mappable resource type... >> >> Hi, >> >> On 17/10/17 14:24, Paul Durrant wrote: >>> diff --git a/xen/common/memory.c b/xen/common/memory.c >>> index cdd2e030cf..b27a71c4f1 100644 >>> --- a/xen/common/memory.c >>> +++ b/xen/common/memory.c >>> @@ -1011,6 +1011,11 @@ static int acquire_resource( >>> >>> switch ( xmar.type ) >>> { >>> + case XENMEM_resource_ioreq_server: >>> + rc = xenmem_acquire_ioreq_server(d, xmar.id, xmar.frame, >>> + xmar.nr_frames, mfn_list); >>> + break; >> >> I fully appreciate you are not able to test on x86. However, I would >> have expected you to at least build test it. >> > > I don't actually know how to set up cross-compilation, which is why I'd originally #ifdef-ed this. It is quite trivial. See https://wiki.xenproject.org/wiki/Xen_ARM_with_Virtualization_Extensions#Cross_Compiling
> -----Original Message----- > From: Julien Grall [mailto:julien.grall@linaro.org] > Sent: 19 October 2017 14:08 > To: Paul Durrant <Paul.Durrant@citrix.com>; xen-devel@lists.xenproject.org > Cc: Stefano Stabellini <sstabellini@kernel.org>; Wei Liu > <wei.liu2@citrix.com>; Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>; > George Dunlap <George.Dunlap@citrix.com>; Andrew Cooper > <Andrew.Cooper3@citrix.com>; Ian Jackson <Ian.Jackson@citrix.com>; Tim > (Xen.org) <tim@xen.org>; Jan Beulich <jbeulich@suse.com> > Subject: Re: [Xen-devel] [PATCH v12 06/11] x86/hvm/ioreq: add a new > mappable resource type... > > Hi Paul, > > On 10/19/2017 01:58 PM, Paul Durrant wrote: > >> -----Original Message----- > >> From: Julien Grall [mailto:julien.grall@linaro.org] > >> Sent: 19 October 2017 13:31 > >> To: Paul Durrant <Paul.Durrant@citrix.com>; xen- > devel@lists.xenproject.org > >> Cc: Stefano Stabellini <sstabellini@kernel.org>; Wei Liu > >> <wei.liu2@citrix.com>; Konrad Rzeszutek Wilk > <konrad.wilk@oracle.com>; > >> George Dunlap <George.Dunlap@citrix.com>; Andrew Cooper > >> <Andrew.Cooper3@citrix.com>; Ian Jackson <Ian.Jackson@citrix.com>; > Tim > >> (Xen.org) <tim@xen.org>; Jan Beulich <jbeulich@suse.com> > >> Subject: Re: [Xen-devel] [PATCH v12 06/11] x86/hvm/ioreq: add a new > >> mappable resource type... > >> > >> Hi, > >> > >> On 17/10/17 14:24, Paul Durrant wrote: > >>> diff --git a/xen/common/memory.c b/xen/common/memory.c > >>> index cdd2e030cf..b27a71c4f1 100644 > >>> --- a/xen/common/memory.c > >>> +++ b/xen/common/memory.c > >>> @@ -1011,6 +1011,11 @@ static int acquire_resource( > >>> > >>> switch ( xmar.type ) > >>> { > >>> + case XENMEM_resource_ioreq_server: > >>> + rc = xenmem_acquire_ioreq_server(d, xmar.id, xmar.frame, > >>> + xmar.nr_frames, mfn_list); > >>> + break; > >> > >> I fully appreciate you are not able to test on x86. However, I would > >> have expected you to at least build test it. > >> > > > > I don't actually know how to set up cross-compilation, which is why I'd > originally #ifdef-ed this. > > It is quite trivial. See > https://wiki.xenproject.org/wiki/Xen_ARM_with_Virtualization_Extensions# > Cross_Compiling > Oh, that's way more trivial than I'd imagined. Thanks! Paul > -- > Julien Grall
>>> On 17.10.17 at 15:24, <paul.durrant@citrix.com> wrote: > @@ -777,6 +887,52 @@ int hvm_get_ioreq_server_info(struct domain *d, ioservid_t id, > return rc; > } > > +int hvm_get_ioreq_server_frame(struct domain *d, ioservid_t id, There's another silent truncation issue here: Iirc ioservid_t is 16 bits. > @@ -3866,6 +3867,27 @@ int xenmem_add_to_physmap_one( > return rc; > } > > +int xenmem_acquire_ioreq_server(struct domain *d, unsigned int id, > + unsigned long frame, > + unsigned int nr_frames, > + unsigned long mfn_list[]) > +{ > + unsigned int i; > + > + for ( i = 0; i < nr_frames; i++ ) > + { > + mfn_t mfn; > + int rc = hvm_get_ioreq_server_frame(d, id, frame + i, &mfn); The caller here holds a 32-bit quantity in its hands, though. With the upper half suitably checked in either place Reviewed-by: Jan Beulich <jbeulich@suse.com> Jan
diff --git a/xen/arch/x86/hvm/ioreq.c b/xen/arch/x86/hvm/ioreq.c index f654e7796c..2c611fbffa 100644 --- a/xen/arch/x86/hvm/ioreq.c +++ b/xen/arch/x86/hvm/ioreq.c @@ -259,6 +259,19 @@ static int hvm_map_ioreq_gfn(struct hvm_ioreq_server *s, bool buf) struct hvm_ioreq_page *iorp = buf ? &s->bufioreq : &s->ioreq; int rc; + if ( iorp->page ) + { + /* + * If a page has already been allocated (which will happen on + * demand if hvm_get_ioreq_server_frame() is called), then + * mapping a guest frame is not permitted. + */ + if ( gfn_eq(iorp->gfn, INVALID_GFN) ) + return -EPERM; + + return 0; + } + if ( d->is_dying ) return -EINVAL; @@ -281,6 +294,70 @@ static int hvm_map_ioreq_gfn(struct hvm_ioreq_server *s, bool buf) return rc; } +static int hvm_alloc_ioreq_mfn(struct hvm_ioreq_server *s, bool buf) +{ + struct domain *currd = current->domain; + struct hvm_ioreq_page *iorp = buf ? &s->bufioreq : &s->ioreq; + + if ( iorp->page ) + { + /* + * If a guest frame has already been mapped (which may happen + * on demand if hvm_get_ioreq_server_info() is called), then + * allocating a page is not permitted. + */ + if ( !gfn_eq(iorp->gfn, INVALID_GFN) ) + return -EPERM; + + return 0; + } + + /* + * Allocated IOREQ server pages are assigned to the emulating + * domain, not the target domain. This is because the emulator is + * likely to be destroyed after the target domain has been torn + * down, and we must use MEMF_no_refcount otherwise page allocation + * could fail if the emulating domain has already reached its + * maximum allocation. + */ + iorp->page = alloc_domheap_page(currd, MEMF_no_refcount); + if ( !iorp->page ) + return -ENOMEM; + + if ( !get_page_type(iorp->page, PGT_writable_page) ) + { + ASSERT_UNREACHABLE(); + put_page(iorp->page); + iorp->page = NULL; + return -ENOMEM; + } + + iorp->va = __map_domain_page_global(iorp->page); + if ( !iorp->va ) + { + put_page_and_type(iorp->page); + iorp->page = NULL; + return -ENOMEM; + } + + clear_page(iorp->va); + return 0; +} + +static void hvm_free_ioreq_mfn(struct hvm_ioreq_server *s, bool buf) +{ + struct hvm_ioreq_page *iorp = buf ? &s->bufioreq : &s->ioreq; + + if ( !iorp->page ) + return; + + unmap_domain_page_global(iorp->va); + iorp->va = NULL; + + put_page_and_type(iorp->page); + iorp->page = NULL; +} + bool is_ioreq_server_page(struct domain *d, const struct page_info *page) { const struct hvm_ioreq_server *s; @@ -484,6 +561,27 @@ static void hvm_ioreq_server_unmap_pages(struct hvm_ioreq_server *s) hvm_unmap_ioreq_gfn(s, false); } +static int hvm_ioreq_server_alloc_pages(struct hvm_ioreq_server *s) +{ + int rc; + + rc = hvm_alloc_ioreq_mfn(s, false); + + if ( !rc && (s->bufioreq_handling != HVM_IOREQSRV_BUFIOREQ_OFF) ) + rc = hvm_alloc_ioreq_mfn(s, true); + + if ( rc ) + hvm_free_ioreq_mfn(s, false); + + return rc; +} + +static void hvm_ioreq_server_free_pages(struct hvm_ioreq_server *s) +{ + hvm_free_ioreq_mfn(s, true); + hvm_free_ioreq_mfn(s, false); +} + static void hvm_ioreq_server_free_rangesets(struct hvm_ioreq_server *s) { unsigned int i; @@ -612,7 +710,18 @@ static int hvm_ioreq_server_init(struct hvm_ioreq_server *s, fail_add: hvm_ioreq_server_remove_all_vcpus(s); + + /* + * NOTE: It is safe to call both hvm_ioreq_server_unmap_pages() and + * hvm_ioreq_server_free_pages() in that order. + * This is because the former will do nothing if the pages + * are not mapped, leaving the page to be freed by the latter. + * However if the pages are mapped then the former will set + * the page_info pointer to NULL, meaning the latter will do + * nothing. + */ hvm_ioreq_server_unmap_pages(s); + hvm_ioreq_server_free_pages(s); return rc; } @@ -622,6 +731,7 @@ static void hvm_ioreq_server_deinit(struct hvm_ioreq_server *s) ASSERT(!s->enabled); hvm_ioreq_server_remove_all_vcpus(s); hvm_ioreq_server_unmap_pages(s); + hvm_ioreq_server_free_pages(s); hvm_ioreq_server_free_rangesets(s); } @@ -777,6 +887,52 @@ int hvm_get_ioreq_server_info(struct domain *d, ioservid_t id, return rc; } +int hvm_get_ioreq_server_frame(struct domain *d, ioservid_t id, + unsigned long idx, mfn_t *mfn) +{ + struct hvm_ioreq_server *s; + int rc; + + spin_lock_recursive(&d->arch.hvm_domain.ioreq_server.lock); + + if ( id == DEFAULT_IOSERVID ) + return -EOPNOTSUPP; + + s = get_ioreq_server(d, id); + + ASSERT(!IS_DEFAULT(s)); + + rc = hvm_ioreq_server_alloc_pages(s); + if ( rc ) + goto out; + + switch ( idx ) + { + case XENMEM_resource_ioreq_server_frame_bufioreq: + rc = -ENOENT; + if ( !HANDLE_BUFIOREQ(s) ) + goto out; + + *mfn = _mfn(page_to_mfn(s->bufioreq.page)); + rc = 0; + break; + + case XENMEM_resource_ioreq_server_frame_ioreq(0): + *mfn = _mfn(page_to_mfn(s->ioreq.page)); + rc = 0; + break; + + default: + rc = -EINVAL; + break; + } + + out: + spin_unlock_recursive(&d->arch.hvm_domain.ioreq_server.lock); + + return rc; +} + int hvm_map_io_range_to_ioreq_server(struct domain *d, ioservid_t id, uint32_t type, uint64_t start, uint64_t end) diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c index d9df5ca69f..1d15ae2a15 100644 --- a/xen/arch/x86/mm.c +++ b/xen/arch/x86/mm.c @@ -122,6 +122,7 @@ #include <asm/fixmap.h> #include <asm/io_apic.h> #include <asm/pci.h> +#include <asm/hvm/ioreq.h> #include <asm/hvm/grant_table.h> #include <asm/pv/grant_table.h> @@ -3866,6 +3867,27 @@ int xenmem_add_to_physmap_one( return rc; } +int xenmem_acquire_ioreq_server(struct domain *d, unsigned int id, + unsigned long frame, + unsigned int nr_frames, + unsigned long mfn_list[]) +{ + unsigned int i; + + for ( i = 0; i < nr_frames; i++ ) + { + mfn_t mfn; + int rc = hvm_get_ioreq_server_frame(d, id, frame + i, &mfn); + + if ( rc ) + return rc; + + mfn_list[i] = mfn_x(mfn); + } + + return 0; +} + long arch_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg) { int rc; diff --git a/xen/common/memory.c b/xen/common/memory.c index cdd2e030cf..b27a71c4f1 100644 --- a/xen/common/memory.c +++ b/xen/common/memory.c @@ -1011,6 +1011,11 @@ static int acquire_resource( switch ( xmar.type ) { + case XENMEM_resource_ioreq_server: + rc = xenmem_acquire_ioreq_server(d, xmar.id, xmar.frame, + xmar.nr_frames, mfn_list); + break; + default: rc = -EOPNOTSUPP; break; diff --git a/xen/include/asm-x86/hvm/ioreq.h b/xen/include/asm-x86/hvm/ioreq.h index 1829fcf43e..9e37c97a37 100644 --- a/xen/include/asm-x86/hvm/ioreq.h +++ b/xen/include/asm-x86/hvm/ioreq.h @@ -31,6 +31,8 @@ int hvm_get_ioreq_server_info(struct domain *d, ioservid_t id, unsigned long *ioreq_gfn, unsigned long *bufioreq_gfn, evtchn_port_t *bufioreq_port); +int hvm_get_ioreq_server_frame(struct domain *d, ioservid_t id, + unsigned long idx, mfn_t *mfn); int hvm_map_io_range_to_ioreq_server(struct domain *d, ioservid_t id, uint32_t type, uint64_t start, uint64_t end); diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h index f2e0f498c4..44aac9d225 100644 --- a/xen/include/asm-x86/mm.h +++ b/xen/include/asm-x86/mm.h @@ -615,4 +615,9 @@ static inline bool arch_mfn_in_directmap(unsigned long mfn) return mfn <= (virt_to_mfn(eva - 1) + 1); } +int xenmem_acquire_ioreq_server(struct domain *d, unsigned int id, + unsigned long frame, + unsigned int nr_frames, + unsigned long mfn_list[]); + #endif /* __ASM_X86_MM_H__ */ diff --git a/xen/include/public/hvm/dm_op.h b/xen/include/public/hvm/dm_op.h index 9677bd74e7..59b6006910 100644 --- a/xen/include/public/hvm/dm_op.h +++ b/xen/include/public/hvm/dm_op.h @@ -90,6 +90,10 @@ struct xen_dm_op_create_ioreq_server { * the frame numbers passed back in gfns <ioreq_gfn> and <bufioreq_gfn> * respectively. (If the IOREQ Server is not handling buffered emulation * only <ioreq_gfn> will be valid). + * + * NOTE: To access the synchronous ioreq structures and buffered ioreq + * ring, it is preferable to use the XENMEM_acquire_resource memory + * op specifying resource type XENMEM_resource_ioreq_server. */ #define XEN_DMOP_get_ioreq_server_info 2 diff --git a/xen/include/public/memory.h b/xen/include/public/memory.h index 18118ea5c6..9596ebf2c7 100644 --- a/xen/include/public/memory.h +++ b/xen/include/public/memory.h @@ -609,9 +609,14 @@ struct xen_mem_acquire_resource { domid_t domid; /* IN - the type of resource */ uint16_t type; + +#define XENMEM_resource_ioreq_server 0 + /* * IN - a type-specific resource identifier, which must be zero * unless stated otherwise. + * + * type == XENMEM_resource_ioreq_server -> id == ioreq server id */ uint32_t id; /* IN/OUT - As an IN parameter number of frames of the resource @@ -625,6 +630,10 @@ struct xen_mem_acquire_resource { * is ignored if nr_frames is 0. */ uint64_aligned_t frame; + +#define XENMEM_resource_ioreq_server_frame_bufioreq 0 +#define XENMEM_resource_ioreq_server_frame_ioreq(n) (1 + (n)) + /* IN/OUT - If the tools domain is PV then, upon return, frame_list * will be populated with the MFNs of the resource. * If the tools domain is HVM then it is expected that, on
... XENMEM_resource_ioreq_server This patch adds support for a new resource type that can be mapped using the XENMEM_acquire_resource memory op. If an emulator makes use of this resource type then, instead of mapping gfns, the IOREQ server will allocate pages from the heap. These pages will never be present in the P2M of the guest at any point and so are not vulnerable to any direct attack by the guest. They are only ever accessible by Xen and any domain that has mapping privilege over the guest (which may or may not be limited to the domain running the emulator). NOTE: Use of the new resource type is not compatible with use of XEN_DMOP_get_ioreq_server_info unless the XEN_DMOP_no_gfns flag is set. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> --- Cc: George Dunlap <George.Dunlap@eu.citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Jan Beulich <jbeulich@suse.com> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Ian Jackson <ian.jackson@eu.citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Tim Deegan <tim@xen.org> v12: - Addressed more comments from Jan. - Dropped George's A-b and Wei's R-b because of material change. v11: - Addressed more comments from Jan. v10: - Addressed comments from Jan. v8: - Re-base on new boilerplate. - Adjust function signature of hvm_get_ioreq_server_frame(), and test whether the bufioreq page is present. v5: - Use get_ioreq_server() function rather than indexing array directly. - Add more explanation into comments to state than mapping guest frames and allocation of pages for ioreq servers are not simultaneously permitted. - Add a comment into asm/ioreq.h stating the meaning of the index value passed to hvm_get_ioreq_server_frame(). --- xen/arch/x86/hvm/ioreq.c | 156 ++++++++++++++++++++++++++++++++++++++++ xen/arch/x86/mm.c | 22 ++++++ xen/common/memory.c | 5 ++ xen/include/asm-x86/hvm/ioreq.h | 2 + xen/include/asm-x86/mm.h | 5 ++ xen/include/public/hvm/dm_op.h | 4 ++ xen/include/public/memory.h | 9 +++ 7 files changed, 203 insertions(+)