From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Gibson Subject: Re: [PATCH v2 13/16] KVM: PPC: Book3S HV: XIVE: add a mapping for the source ESB pages Date: Mon, 25 Feb 2019 14:47:26 +1100 Message-ID: <20190225034726.GQ7668@umbus.fritz.box> References: <20190222112840.25000-1-clg@kaod.org> <20190222112840.25000-14-clg@kaod.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="mzmkN2k+aDjaU9Rr" Cc: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, Paul Mackerras , linuxppc-dev@lists.ozlabs.org To: =?iso-8859-1?Q?C=E9dric?= Le Goater Return-path: Content-Disposition: inline In-Reply-To: <20190222112840.25000-14-clg@kaod.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+glppe-linuxppc-embedded-2=m.gmane.org@lists.ozlabs.org Sender: "Linuxppc-dev" List-Id: kvm.vger.kernel.org --mzmkN2k+aDjaU9Rr Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Feb 22, 2019 at 12:28:37PM +0100, C=E9dric Le Goater wrote: > Each source is associated with an Event State Buffer (ESB) with a > even/odd pair of pages which provides commands to manage the source: > to trigger, to EOI, to turn off the source for instance. >=20 > The custom VM fault handler will deduce the guest IRQ number from the > offset of the fault, and the ESB page of the associated XIVE interrupt > will be inserted into the VMA using the internal structure caching > information on the interrupts. >=20 > Signed-off-by: C=E9dric Le Goater Reviewed-by: David Gibson With the same caveat as the previous patch. > --- > arch/powerpc/include/uapi/asm/kvm.h | 1 + > arch/powerpc/kvm/book3s_xive_native.c | 57 ++++++++++++++++++++++ > Documentation/virtual/kvm/devices/xive.txt | 7 +++ > 3 files changed, 65 insertions(+) >=20 > diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/u= api/asm/kvm.h > index be9b255e061d..d8990e9044e3 100644 > --- a/arch/powerpc/include/uapi/asm/kvm.h > +++ b/arch/powerpc/include/uapi/asm/kvm.h > @@ -721,5 +721,6 @@ struct kvm_ppc_xive_eq { > #define KVM_XIVE_EQ_FLAG_ESCALATE 0x00000004 > =20 > #define KVM_XIVE_TIMA_PAGE_OFFSET 0 > +#define KVM_XIVE_ESB_PAGE_OFFSET 4 > =20 > #endif /* __LINUX_KVM_POWERPC_H */ > diff --git a/arch/powerpc/kvm/book3s_xive_native.c b/arch/powerpc/kvm/boo= k3s_xive_native.c > index c6ac818a13b2..92cab6409e8e 100644 > --- a/arch/powerpc/kvm/book3s_xive_native.c > +++ b/arch/powerpc/kvm/book3s_xive_native.c > @@ -176,6 +176,59 @@ int kvmppc_xive_native_connect_vcpu(struct kvm_devic= e *dev, > return rc; > } > =20 > +static int xive_native_esb_fault(struct vm_fault *vmf) > +{ > + struct vm_area_struct *vma =3D vmf->vma; > + struct kvm_device *dev =3D vma->vm_file->private_data; > + struct kvmppc_xive *xive =3D dev->private; > + struct kvmppc_xive_src_block *sb; > + struct kvmppc_xive_irq_state *state; > + struct xive_irq_data *xd; > + u32 hw_num; > + u16 src; > + u64 page; > + unsigned long irq; > + u64 page_offset; > + > + /* > + * Linux/KVM uses a two pages ESB setting, one for trigger and > + * one for EOI > + */ > + page_offset =3D vmf->pgoff - vma->vm_pgoff; > + irq =3D page_offset / 2; > + > + sb =3D kvmppc_xive_find_source(xive, irq, &src); > + if (!sb) { > + pr_devel("%s: source %lx not found !\n", __func__, irq); > + return VM_FAULT_SIGBUS; > + } > + > + state =3D &sb->irq_state[src]; > + kvmppc_xive_select_irq(state, &hw_num, &xd); > + > + arch_spin_lock(&sb->lock); > + > + /* > + * first/even page is for trigger > + * second/odd page is for EOI and management. > + */ > + page =3D page_offset % 2 ? xd->eoi_page : xd->trig_page; > + arch_spin_unlock(&sb->lock); > + > + if (WARN_ON(!page)) { > + pr_err("%s: acessing invalid ESB page for source %lx !\n", > + __func__, irq); > + return VM_FAULT_SIGBUS; > + } > + > + vmf_insert_pfn(vma, vmf->address, page >> PAGE_SHIFT); > + return VM_FAULT_NOPAGE; > +} > + > +static const struct vm_operations_struct xive_native_esb_vmops =3D { > + .fault =3D xive_native_esb_fault, > +}; > + > static int xive_native_tima_fault(struct vm_fault *vmf) > { > struct vm_area_struct *vma =3D vmf->vma; > @@ -205,6 +258,10 @@ static int kvmppc_xive_native_mmap(struct kvm_device= *dev, > if (vma_pages(vma) > 4) > return -EINVAL; > vma->vm_ops =3D &xive_native_tima_vmops; > + } else if (vma->vm_pgoff =3D=3D KVM_XIVE_ESB_PAGE_OFFSET) { > + if (vma_pages(vma) > KVMPPC_XIVE_NR_IRQS * 2) > + return -EINVAL; > + vma->vm_ops =3D &xive_native_esb_vmops; > } else { > return -EINVAL; > } > diff --git a/Documentation/virtual/kvm/devices/xive.txt b/Documentation/v= irtual/kvm/devices/xive.txt > index 4d6b41609fd9..be5000b2eb5a 100644 > --- a/Documentation/virtual/kvm/devices/xive.txt > +++ b/Documentation/virtual/kvm/devices/xive.txt > @@ -36,6 +36,13 @@ the legacy interrupt mode, referred as XICS (POWER7/8). > third (operating system) and the fourth (user level) are exposed the > guest. > =20 > + 2. Event State Buffer (ESB) > + > + Each source is associated with an Event State Buffer (ESB) with > + either a pair of even/odd pair of pages which provides commands to > + manage the source: to trigger, to EOI, to turn off the source for > + instance. > + > * Groups: > =20 > 1. KVM_DEV_XIVE_GRP_CTRL --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. 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