[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH RESEND v9 04/14] arch/arm: unmap partially-mapped I/O-memory regions
This commit changes the function apply_p2m_changes() to unwind changes performed while mapping an I/O-memory region, if errors are seen during the operation. This is useful to avoid that I/O-memory areas are partially accessible to guests. Signed-off-by: Arianna Avanzini <avanzini.arianna@xxxxxxxxx> Cc: Dario Faggioli <dario.faggioli@xxxxxxxxxx> Cc: Paolo Valente <paolo.valente@xxxxxxxxxx> Cc: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx> Cc: Julien Grall <julien.grall@xxxxxxxxxx> Cc: Ian Campbell <Ian.Campbell@xxxxxxxxxxxxx> Cc: Jan Beulich <jbeulich@xxxxxxxx> Cc: Keir Fraser <keir@xxxxxxx> Cc: Tim Deegan <tim@xxxxxxx> Cc: Ian Jackson <Ian.Jackson@xxxxxxxxxxxxx> Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> Cc: Eric Trudeau <etrudeau@xxxxxxxxxxxx> Cc: Viktor Kleinik <viktor.kleinik@xxxxxxxxxxxxxxx> --- v9: - Let apply_p2m_ranges() unwind its own progress instead of relying on the caller to unmap partially-mapped I/O-memory regions. - Adapt to rework of p2m-related functions for ARM. --- xen/arch/arm/p2m.c | 33 +++++++++++++++++++++++++++++---- 1 file changed, 29 insertions(+), 4 deletions(-) diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c index 1e6579f..e9f7c96 100644 --- a/xen/arch/arm/p2m.c +++ b/xen/arch/arm/p2m.c @@ -694,7 +694,7 @@ static int apply_p2m_changes(struct domain *d, unsigned long cur_first_page = ~0, cur_first_offset = ~0, cur_second_offset = ~0; - unsigned long count = 0; + unsigned long count = 0, inserted = 0; bool_t flush = false; bool_t flush_pt; @@ -706,6 +706,7 @@ static int apply_p2m_changes(struct domain *d, spin_lock(&p2m->lock); +unwind: addr = start_gpaddr; while ( addr < end_gpaddr ) { @@ -749,7 +750,15 @@ static int apply_p2m_changes(struct domain *d, start_gpaddr, end_gpaddr, &addr, &maddr, &flush, mattr, t); - if ( ret < 0 ) { rc = ret ; goto out; } + if ( ret < 0 ) + { + rc = ret ; + if ( op != INSERT ) goto out; + end_gpaddr = start_gpaddr + inserted * PAGE_SIZE; + op = REMOVE; + goto unwind; + } + if ( op == INSERT ) inserted++; count += ret; if ( ret != P2M_ONE_DESCEND ) continue; @@ -768,7 +777,15 @@ static int apply_p2m_changes(struct domain *d, start_gpaddr, end_gpaddr, &addr, &maddr, &flush, mattr, t); - if ( ret < 0 ) { rc = ret ; goto out; } + if ( ret < 0 ) + { + rc = ret ; + if ( op != INSERT ) goto out; + end_gpaddr = start_gpaddr + inserted * PAGE_SIZE; + op = REMOVE; + goto unwind; + } + if ( op == INSERT ) inserted++; count += ret; if ( ret != P2M_ONE_DESCEND ) continue; @@ -787,9 +804,17 @@ static int apply_p2m_changes(struct domain *d, start_gpaddr, end_gpaddr, &addr, &maddr, &flush, mattr, t); - if ( ret < 0 ) { rc = ret ; goto out; } + if ( ret < 0 ) + { + rc = ret ; + if ( op != INSERT ) goto out; + end_gpaddr = start_gpaddr + inserted * PAGE_SIZE; + op = REMOVE; + goto unwind; + } /* L3 had better have done something! We cannot descend any further */ BUG_ON(ret == P2M_ONE_DESCEND); + if ( op == INSERT ) inserted++; count += ret; } -- 1.9.3 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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