From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54523) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cUUcJ-0002oY-D5 for qemu-devel@nongnu.org; Fri, 20 Jan 2017 03:32:16 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cUUcG-0007Us-6a for qemu-devel@nongnu.org; Fri, 20 Jan 2017 03:32:15 -0500 Received: from mga05.intel.com ([192.55.52.43]:5513) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cUUcF-0007UZ-TM for qemu-devel@nongnu.org; Fri, 20 Jan 2017 03:32:12 -0500 From: "Tian, Kevin" Date: Fri, 20 Jan 2017 08:32:06 +0000 Message-ID: References: <1484276800-26814-1-git-send-email-peterx@redhat.com> <1484276800-26814-2-git-send-email-peterx@redhat.com> In-Reply-To: <1484276800-26814-2-git-send-email-peterx@redhat.com> Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH RFC v3 01/14] IOMMU: add option to enable VTD_CAP_CM to vIOMMU capility exposoed to guest List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Xu , "qemu-devel@nongnu.org" Cc: "Lan, Tianyu" , "mst@redhat.com" , "jan.kiszka@siemens.com" , "jasowang@redhat.com" , "alex.williamson@redhat.com" , "bd.aviv@gmail.com" > From: Peter Xu [mailto:peterx@redhat.com] > Sent: Friday, January 13, 2017 11:06 AM >=20 > From: Aviv Ben-David >=20 > This capability asks the guest to invalidate cache before each map operat= ion. > We can use this invalidation to trap map operations in the hypervisor. >=20 > Signed-off-by: Aviv Ben-David > Signed-off-by: Peter Xu > --- > hw/i386/intel_iommu.c | 5 +++++ > hw/i386/intel_iommu_internal.h | 1 + > include/hw/i386/intel_iommu.h | 2 ++ > 3 files changed, 8 insertions(+) >=20 > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c > index ec62239..2868e37 100644 > --- a/hw/i386/intel_iommu.c > +++ b/hw/i386/intel_iommu.c > @@ -2107,6 +2107,7 @@ static Property vtd_properties[] =3D { > DEFINE_PROP_ON_OFF_AUTO("eim", IntelIOMMUState, intr_eim, > ON_OFF_AUTO_AUTO), > DEFINE_PROP_BOOL("x-buggy-eim", IntelIOMMUState, buggy_eim, false), > + DEFINE_PROP_BOOL("cache-mode", IntelIOMMUState, cache_mode_enabled, > FALSE), > DEFINE_PROP_END_OF_LIST(), > }; >=20 > @@ -2488,6 +2489,10 @@ static void vtd_init(IntelIOMMUState *s) > s->ecap |=3D VTD_ECAP_DT; > } >=20 > + if (s->cache_mode_enabled) { > + s->cap |=3D VTD_CAP_CM; > + } > + I think some of my old comments are not answered: 1) Better to use caching_mode to follow spec 2) Does it make sense to automatically set this flag if any VFIO device has been statically assigned when starting Qemu? Also for hot-add device path, some check of caching mode is required. If not set,=20 should we fail hot-add operation? I don't think we have such physical platform with some devices behind IOMMU while others not. > vtd_reset_context_cache(s); > vtd_reset_iotlb(s); >=20 > diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_interna= l.h > index 356f188..4104121 100644 > --- a/hw/i386/intel_iommu_internal.h > +++ b/hw/i386/intel_iommu_internal.h > @@ -202,6 +202,7 @@ > #define VTD_CAP_MAMV (VTD_MAMV << 48) > #define VTD_CAP_PSI (1ULL << 39) > #define VTD_CAP_SLLPS ((1ULL << 34) | (1ULL << 35)) > +#define VTD_CAP_CM (1ULL << 7) >=20 > /* Supported Adjusted Guest Address Widths */ > #define VTD_CAP_SAGAW_SHIFT 8 > diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.= h > index 405c9d1..749eef9 100644 > --- a/include/hw/i386/intel_iommu.h > +++ b/include/hw/i386/intel_iommu.h > @@ -257,6 +257,8 @@ struct IntelIOMMUState { > uint8_t womask[DMAR_REG_SIZE]; /* WO (write only - read returns 0) = */ > uint32_t version; >=20 > + bool cache_mode_enabled; /* RO - is cap CM enabled? */ > + > dma_addr_t root; /* Current root table pointer */ > bool root_extended; /* Type of root table (extended or n= ot) */ > bool dmar_enabled; /* Set if DMA remapping is enabled *= / > -- > 2.7.4