Re: [PATCH 1/9] KVM: arm64: vgic-v3: Fix some error codes when setting RDIST base
Hi Alexandru, On 1/6/21 5:32 PM, Alexandru Elisei wrote: > Hi Eric, > > On 12/12/20 6:50 PM, Eric Auger wrote: >> KVM_DEV_ARM_VGIC_GRP_ADDR group doc says we should return >> -EEXIST in case the base address of the redist is already set. >> We currently return -EINVAL. >> >> However we need to return -EINVAL in case a legacy REDIST address >> is attempted to be set while REDIST_REGIONS were set. This case >> is discriminated by looking at the count field. >> >> Signed-off-by: Eric Auger >> --- >> arch/arm64/kvm/vgic/vgic-mmio-v3.c | 9 +++-- >> 1 file changed, 7 insertions(+), 2 deletions(-) >> >> diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c >> b/arch/arm64/kvm/vgic/vgic-mmio-v3.c >> index 15a6c98ee92f..8e8a862def76 100644 >> --- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c >> +++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c >> @@ -792,8 +792,13 @@ static int vgic_v3_insert_redist_region(struct kvm >> *kvm, uint32_t index, >> int ret; >> >> /* single rdist region already set ?*/ >> -if (!count && !list_empty(rd_regions)) >> -return -EINVAL; >> +if (!count && !list_empty(rd_regions)) { >> +rdreg = list_last_entry(rd_regions, >> + struct vgic_redist_region, list); >> +if (rdreg->count) >> +return -EINVAL; /* Mixing REDIST and REDIST_REGION API >> */ >> +return -EEXIST; >> +} > > A few instructions below: > > if (list_empty(rd_regions)) { > [..] > } else { > rdreg = list_last_entry(rd_regions, > struct vgic_redist_region, list); > [..] > > /* Cannot add an explicitly sized regions after legacy region */ > if (!rdreg->count) > return -EINVAL; > } > > Isn't this testing for the same thing, but using the opposite condition? Or > am I > misunderstanding the code (quite likely)? the 1st test sequence handles the case where the legacy KVM_VGIC_V3_ADDR_TYPE_REDIST is used (!count) while the second handles the case where the REDIST_REGION is used. Nevertheless I think this can be simplified into: if (list_empty(rd_regions)) { if (index != 0) return -EINVAL; } else { rdreg = list_last_entry(rd_regions, struct vgic_redist_region, list); if ((!count) != (!rdreg->count)) return -EINVAL; /* Mix REDIST and REDIST_REGION */ if (!count) return -EEXIST; if (index != rdreg->index + 1) return -EINVAL; } > > Looks to me like > KVM_DEV_ARM_VGIC_GRP_ADDR(KVM_VGIC_V3_ADDR_TYPE_REDIST{,_REGION}) > used to return -EEXIST (from vgic_check_ioaddr()) before commit ccc27bf5be7b7 > ("KVM: arm/arm64: Helper to register a new redistributor region") which added > the > vgic_v3_insert_redist_region() function, so bringing back the -EEXIST return > code > looks the right thing to me. OK thank you for the detailed study. Eric > > Thanks, > Alex >> >> /* cross the end of memory ? */ >> if (base + size < base) >
Re: [PATCH 1/9] KVM: arm64: vgic-v3: Fix some error codes when setting RDIST base
Hi Eric, On 12/12/20 6:50 PM, Eric Auger wrote: > KVM_DEV_ARM_VGIC_GRP_ADDR group doc says we should return > -EEXIST in case the base address of the redist is already set. > We currently return -EINVAL. > > However we need to return -EINVAL in case a legacy REDIST address > is attempted to be set while REDIST_REGIONS were set. This case > is discriminated by looking at the count field. > > Signed-off-by: Eric Auger > --- > arch/arm64/kvm/vgic/vgic-mmio-v3.c | 9 +++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c > b/arch/arm64/kvm/vgic/vgic-mmio-v3.c > index 15a6c98ee92f..8e8a862def76 100644 > --- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c > +++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c > @@ -792,8 +792,13 @@ static int vgic_v3_insert_redist_region(struct kvm *kvm, > uint32_t index, > int ret; > > /* single rdist region already set ?*/ > - if (!count && !list_empty(rd_regions)) > - return -EINVAL; > + if (!count && !list_empty(rd_regions)) { > + rdreg = list_last_entry(rd_regions, > +struct vgic_redist_region, list); > + if (rdreg->count) > + return -EINVAL; /* Mixing REDIST and REDIST_REGION API > */ > + return -EEXIST; > + } A few instructions below: if (list_empty(rd_regions)) { [..] } else { rdreg = list_last_entry(rd_regions, struct vgic_redist_region, list); [..] /* Cannot add an explicitly sized regions after legacy region */ if (!rdreg->count) return -EINVAL; } Isn't this testing for the same thing, but using the opposite condition? Or am I misunderstanding the code (quite likely)? Looks to me like KVM_DEV_ARM_VGIC_GRP_ADDR(KVM_VGIC_V3_ADDR_TYPE_REDIST{,_REGION}) used to return -EEXIST (from vgic_check_ioaddr()) before commit ccc27bf5be7b7 ("KVM: arm/arm64: Helper to register a new redistributor region") which added the vgic_v3_insert_redist_region() function, so bringing back the -EEXIST return code looks the right thing to me. Thanks, Alex > > /* cross the end of memory ? */ > if (base + size < base)
[PATCH 1/9] KVM: arm64: vgic-v3: Fix some error codes when setting RDIST base
KVM_DEV_ARM_VGIC_GRP_ADDR group doc says we should return -EEXIST in case the base address of the redist is already set. We currently return -EINVAL. However we need to return -EINVAL in case a legacy REDIST address is attempted to be set while REDIST_REGIONS were set. This case is discriminated by looking at the count field. Signed-off-by: Eric Auger --- arch/arm64/kvm/vgic/vgic-mmio-v3.c | 9 +++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c index 15a6c98ee92f..8e8a862def76 100644 --- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c +++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c @@ -792,8 +792,13 @@ static int vgic_v3_insert_redist_region(struct kvm *kvm, uint32_t index, int ret; /* single rdist region already set ?*/ - if (!count && !list_empty(rd_regions)) - return -EINVAL; + if (!count && !list_empty(rd_regions)) { + rdreg = list_last_entry(rd_regions, + struct vgic_redist_region, list); + if (rdreg->count) + return -EINVAL; /* Mixing REDIST and REDIST_REGION API */ + return -EEXIST; + } /* cross the end of memory ? */ if (base + size < base) -- 2.21.3