| Message ID | 20170813013346.14002-1-npiggin@gmail.com |
|---|---|
| State | Accepted |
| Headers | show |
Nicholas Piggin <npiggin@gmail.com> writes: > KVM currently validates the size of the VPA registered by the client > against sizeof(struct lppaca), however we align (and therefore size) > that struct to 1kB to avoid crossing a 4kB boundary in the client. > > PAPR calls for sizes >= 640 bytes to be accepted. Hard code this with > a comment. > > Signed-off-by: Nicholas Piggin <npiggin@gmail.com> > --- > arch/powerpc/kvm/book3s_hv.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) This one should go via Paul. Hopefully he can just pick it up. cheers > diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c > index 359c79cdf0cc..1182cfd79857 100644 > --- a/arch/powerpc/kvm/book3s_hv.c > +++ b/arch/powerpc/kvm/book3s_hv.c > @@ -485,7 +485,13 @@ static unsigned long do_h_register_vpa(struct kvm_vcpu *vcpu, > > switch (subfunc) { > case H_VPA_REG_VPA: /* register VPA */ > - if (len < sizeof(struct lppaca)) > + /* > + * The size of our lppaca is 1kB because of the way we align > + * it for the guest to avoid crossing a 4kB boundary. We only > + * use 640 bytes of the structure though, so we should accept > + * clients that set a size of 640. > + */ > + if (len < 640) > break; > vpap = &tvcpu->arch.vpa; > err = 0; > -- > 2.13.3 -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sun, Aug 13, 2017 at 11:33:38AM +1000, Nicholas Piggin wrote: > KVM currently validates the size of the VPA registered by the client > against sizeof(struct lppaca), however we align (and therefore size) > that struct to 1kB to avoid crossing a 4kB boundary in the client. > > PAPR calls for sizes >= 640 bytes to be accepted. Hard code this with > a comment. > > Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Thanks, patch applied to my kvm-ppc-next branch. Paul. -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 359c79cdf0cc..1182cfd79857 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -485,7 +485,13 @@ static unsigned long do_h_register_vpa(struct kvm_vcpu *vcpu, switch (subfunc) { case H_VPA_REG_VPA: /* register VPA */ - if (len < sizeof(struct lppaca)) + /* + * The size of our lppaca is 1kB because of the way we align + * it for the guest to avoid crossing a 4kB boundary. We only + * use 640 bytes of the structure though, so we should accept + * clients that set a size of 640. + */ + if (len < 640) break; vpap = &tvcpu->arch.vpa; err = 0;
KVM currently validates the size of the VPA registered by the client against sizeof(struct lppaca), however we align (and therefore size) that struct to 1kB to avoid crossing a 4kB boundary in the client. PAPR calls for sizes >= 640 bytes to be accepted. Hard code this with a comment. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/kvm/book3s_hv.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)