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X-Received-From: 2a00:1450:4864:20::443 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, Haozhong Zhang , qemu-block@nongnu.org, qemu-devel@nongnu.org, mreitz@redhat.com, keith.busch@intel.com, Zhang Yi , Junyan He , "Dr. David Alan Gilbert" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --OOq1TgGhe8eTwFBO Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Feb 18, 2020 at 03:48:11PM -0700, Andrzej Jakowski wrote: > This patch introduces support for PMR that has been defined as part of NV= Me 1.4 > spec. User can now specify a pmr_file which will be mmap'ed into qemu add= ress > space and subsequently in PCI BAR 2. Guest OS can perform mmio read and w= rites > to the PMR region that will stay persistent accross system reboot. >=20 > Signed-off-by: Andrzej Jakowski > --- > hw/block/nvme.c | 145 ++++++++++++++++++++++++++++++++++- > hw/block/nvme.h | 5 ++ > hw/block/trace-events | 5 ++ > include/block/nvme.h | 172 ++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 326 insertions(+), 1 deletion(-) NVDIMM folks, please take a look. There seems to be commonality here. Can this use -object memory-backend-file instead of manually opening and mapping a file? Also CCing David Gilbert because there is some similarity with the vhost-user-fs's DAX Window feature where QEMU mmaps regions of files into a BAR. > @@ -1303,6 +1327,38 @@ static const MemoryRegionOps nvme_cmb_ops =3D { > }, > }; > =20 > +static void nvme_pmr_write(void *opaque, hwaddr addr, uint64_t data, > + unsigned size) > +{ > + NvmeCtrl *n =3D (NvmeCtrl *)opaque; > + stn_le_p(&n->pmrbuf[addr], size, data); > +} > + > +static uint64_t nvme_pmr_read(void *opaque, hwaddr addr, unsigned size) > +{ > + NvmeCtrl *n =3D (NvmeCtrl *)opaque; > + if (!NVME_PMRCAP_PMRWBM(n->bar.pmrcap)) { > + int ret; > + ret =3D msync(n->pmrbuf, n->f_pmr_size, MS_SYNC); > + if (!ret) { > + NVME_GUEST_ERR(nvme_ub_mmiowr_pmrread_barrier, > + "error while persisting data"); > + } > + } Why is msync(2) done on memory loads instead of stores? --OOq1TgGhe8eTwFBO Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAl5P3xMACgkQnKSrs4Gr c8jK1wgAtCF1ehtsGiKD67pBiQmnHD0LeFGYsbLatsV1x8cbNakmrBZoCEuATB8m avIWo96nGwnugDqdz4bOGQhIQ6o6dd2xuY+DnCokGAgMfNHbN1oeDpN8x8CvMbak dpmmWgVP6EoIj0ynSggAg0/wIwDzc8BuLSJ8rPzN11yvaaZegz3snbHsxllKhBdL 20XFIiYCo0EBEEtAovgcHBF5+KXFfVSn8UtDwgUI0HZU7Qj+wIPTC6ukEvLODk5f uUDQvBxo7Db/47YN3HvCqnJp3Zs1n1ZCMbgsTbjPp0c+iakD14yRhVfmPpY/xMEY oxXOMHB+pJORm7X/8qr38lJFo5PsVQ== =TDKk -----END PGP SIGNATURE----- --OOq1TgGhe8eTwFBO--