| Message ID | 1508224209-15366-3-git-send-email-eric.auger@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Oct 17, 2017 at 09:10:00AM +0200, Eric Auger wrote: > vgic_its_restore_cte returns +1 if the collection table entry > is valid and properly decoded. As a consequence, if the > collection table is fully filled with valid data that are > decoded without error, vgic_its_restore_collection_table() > returns +1. This is wrong. > > Let's use the standard C convention for both vgic_its_restore_cte > and vgic_its_restore_collection_table. vgic_its_restore_cte now > returns whether we have reached the end of the table in the @last > output parameter. vgic_its_restore_collection_table aborts in case > of error or if the end is found. Otherwise, it now returns 0. > > Fixes: ea1ad53e1e31a3 (KVM: arm64: vgic-its: Collection table save/restore) > Signed-off-by: Eric Auger <eric.auger@redhat.com> > > --- > > v2 -> v3: creation > --- > virt/kvm/arm/vgic/vgic-its.c | 40 +++++++++++++++++++++++++++++++--------- > 1 file changed, 31 insertions(+), 9 deletions(-) > > diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c > index eea14a1..a4ff8f7 100644 > --- a/virt/kvm/arm/vgic/vgic-its.c > +++ b/virt/kvm/arm/vgic/vgic-its.c > @@ -2204,7 +2204,19 @@ static int vgic_its_save_cte(struct vgic_its *its, > return kvm_write_guest(its->dev->kvm, gpa, &val, esz); > } > > -static int vgic_its_restore_cte(struct vgic_its *its, gpa_t gpa, int esz) > +/** > + * vgic_its_restore_cte - Restore a collection table entry > + * > + * @its: its handle > + * @gpa: guest physical address of the entry > + * @esz: entry size > + * @last: output boolean indicating whether we have reached the > + * end of the collection table (ie. an invalid entry was decoded) > + * > + * Return: 0 upon success, < 0 on error > + */ > +static int vgic_its_restore_cte(struct vgic_its *its, gpa_t gpa, int esz, > + bool *last) > { > struct its_collection *collection; > struct kvm *kvm = its->dev->kvm; > @@ -2217,7 +2229,8 @@ static int vgic_its_restore_cte(struct vgic_its *its, gpa_t gpa, int esz) > if (ret) > return ret; > val = le64_to_cpu(val); > - if (!(val & KVM_ITS_CTE_VALID_MASK)) > + *last = !(val & KVM_ITS_CTE_VALID_MASK); > + if (*last) > return 0; > > target_addr = (u32)(val >> KVM_ITS_CTE_RDBASE_SHIFT); > @@ -2233,7 +2246,7 @@ static int vgic_its_restore_cte(struct vgic_its *its, gpa_t gpa, int esz) > if (ret) > return ret; > collection->target_addr = target_addr; > - return 1; > + return 0; > } > > /** > @@ -2278,8 +2291,13 @@ static int vgic_its_save_collection_table(struct vgic_its *its) > > /** > * vgic_its_restore_collection_table - reads the collection table > - * in guest memory and restores the ITS internal state. Requires the > - * BASER registers to be restored before. > + * in guest memory and restores the ITS collection cache. > + * > + * @its: its handle > + * > + * Requires the Collection BASER to be previously restored. > + * > + * Returns 0 on success or < 0 on error > */ > static int vgic_its_restore_collection_table(struct vgic_its *its) > { > @@ -2297,13 +2315,17 @@ static int vgic_its_restore_collection_table(struct vgic_its *its) > max_size = GITS_BASER_NR_PAGES(its->baser_coll_table) * SZ_64K; > > while (read < max_size) { > - ret = vgic_its_restore_cte(its, gpa, cte_esz); > - if (ret <= 0) > - break; > + bool last; > + > + ret = vgic_its_restore_cte(its, gpa, cte_esz, &last); > + if (ret < 0 || last) > + return ret; > gpa += cte_esz; > read += cte_esz; > } > - return ret; > + > + /* table was fully filled with valid entries, decoded without error */ > + return 0; > } > > /** > -- > 2.5.5 > It's not that I find this looking particularly elegant, but I'm not sure I have a better alternative, perhaps it's just the natur of the beast: Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c index eea14a1..a4ff8f7 100644 --- a/virt/kvm/arm/vgic/vgic-its.c +++ b/virt/kvm/arm/vgic/vgic-its.c @@ -2204,7 +2204,19 @@ static int vgic_its_save_cte(struct vgic_its *its, return kvm_write_guest(its->dev->kvm, gpa, &val, esz); } -static int vgic_its_restore_cte(struct vgic_its *its, gpa_t gpa, int esz) +/** + * vgic_its_restore_cte - Restore a collection table entry + * + * @its: its handle + * @gpa: guest physical address of the entry + * @esz: entry size + * @last: output boolean indicating whether we have reached the + * end of the collection table (ie. an invalid entry was decoded) + * + * Return: 0 upon success, < 0 on error + */ +static int vgic_its_restore_cte(struct vgic_its *its, gpa_t gpa, int esz, + bool *last) { struct its_collection *collection; struct kvm *kvm = its->dev->kvm; @@ -2217,7 +2229,8 @@ static int vgic_its_restore_cte(struct vgic_its *its, gpa_t gpa, int esz) if (ret) return ret; val = le64_to_cpu(val); - if (!(val & KVM_ITS_CTE_VALID_MASK)) + *last = !(val & KVM_ITS_CTE_VALID_MASK); + if (*last) return 0; target_addr = (u32)(val >> KVM_ITS_CTE_RDBASE_SHIFT); @@ -2233,7 +2246,7 @@ static int vgic_its_restore_cte(struct vgic_its *its, gpa_t gpa, int esz) if (ret) return ret; collection->target_addr = target_addr; - return 1; + return 0; } /** @@ -2278,8 +2291,13 @@ static int vgic_its_save_collection_table(struct vgic_its *its) /** * vgic_its_restore_collection_table - reads the collection table - * in guest memory and restores the ITS internal state. Requires the - * BASER registers to be restored before. + * in guest memory and restores the ITS collection cache. + * + * @its: its handle + * + * Requires the Collection BASER to be previously restored. + * + * Returns 0 on success or < 0 on error */ static int vgic_its_restore_collection_table(struct vgic_its *its) { @@ -2297,13 +2315,17 @@ static int vgic_its_restore_collection_table(struct vgic_its *its) max_size = GITS_BASER_NR_PAGES(its->baser_coll_table) * SZ_64K; while (read < max_size) { - ret = vgic_its_restore_cte(its, gpa, cte_esz); - if (ret <= 0) - break; + bool last; + + ret = vgic_its_restore_cte(its, gpa, cte_esz, &last); + if (ret < 0 || last) + return ret; gpa += cte_esz; read += cte_esz; } - return ret; + + /* table was fully filled with valid entries, decoded without error */ + return 0; } /**
vgic_its_restore_cte returns +1 if the collection table entry is valid and properly decoded. As a consequence, if the collection table is fully filled with valid data that are decoded without error, vgic_its_restore_collection_table() returns +1. This is wrong. Let's use the standard C convention for both vgic_its_restore_cte and vgic_its_restore_collection_table. vgic_its_restore_cte now returns whether we have reached the end of the table in the @last output parameter. vgic_its_restore_collection_table aborts in case of error or if the end is found. Otherwise, it now returns 0. Fixes: ea1ad53e1e31a3 (KVM: arm64: vgic-its: Collection table save/restore) Signed-off-by: Eric Auger <eric.auger@redhat.com> --- v2 -> v3: creation --- virt/kvm/arm/vgic/vgic-its.c | 40 +++++++++++++++++++++++++++++++--------- 1 file changed, 31 insertions(+), 9 deletions(-)