From: Blue Swirl <blauwirbel@gmail.com> To: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: mst@redhat.com, joro@8bytes.org, paul@codesourcery.com, avi@redhat.com, anthony@codemonkey.ws, av1474@comtv.ru, yamahata@valinux.co.jp, kvm@vger.kernel.org, qemu-devel@nongnu.org Subject: Re: [PATCH 3/7] AMD IOMMU emulation Date: Sun, 29 Aug 2010 20:37:14 +0000 [thread overview] Message-ID: <AANLkTik-aWPPQ+Gj3TKg6abeahKJAf0-+Yf76+EkhbAx@mail.gmail.com> (raw) In-Reply-To: <20100828215333.GA7270@localhost> On Sat, Aug 28, 2010 at 9:53 PM, Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> wrote: > On Sat, Aug 28, 2010 at 03:58:23PM +0000, Blue Swirl wrote: >> On Sat, Aug 28, 2010 at 2:54 PM, Eduard - Gabriel Munteanu >> <eduard.munteanu@linux360.ro> wrote: >> > This introduces emulation for the AMD IOMMU, described in "AMD I/O >> > Virtualization Technology (IOMMU) Specification". >> > >> > Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> >> > --- > > [snip] > >> > diff --git a/hw/amd_iommu.c b/hw/amd_iommu.c >> > new file mode 100644 >> > index 0000000..43e0426 >> > --- /dev/null >> > +++ b/hw/amd_iommu.c > > [snip] > >> > +static void amd_iommu_update_mmio(AMDIOMMUState *st, >> > + ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ??target_phys_addr_t addr) >> > +{ >> > + ?? ??size_t reg = addr & ~0x07; >> > + ?? ??uint64_t *base = (uint64_t *) &st->mmio_buf[reg]; >> >> This is still buggy. >> >> > + ?? ??uint64_t val = le64_to_cpu(*base); > > mmio_buf is always LE, so a BE host will have *base in reversed > byteorder. But look at the next line, where I did the le64_to_cpu(). > That should swap the bytes on a BE host, yielding the correct byteorder. Sorry, I missed that one when comparing the patch to previous version. > On a LE host, *base is right the first time and le64_to_cpu() is a nop. > > In any case, I only use 'val', not '*base' directly. I suppose it could > be rewritten for clarity (i.e. ditch 'base'). Yes, someone could add more code later which accidentally uses 'base' directly. > Do you still think it's wrong? Or is it for another reason? I think it's OK for now. The rewrite can happen with a small patch later.
WARNING: multiple messages have this Message-ID (diff)
From: Blue Swirl <blauwirbel@gmail.com> To: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: kvm@vger.kernel.org, mst@redhat.com, joro@8bytes.org, qemu-devel@nongnu.org, yamahata@valinux.co.jp, avi@redhat.com, paul@codesourcery.com Subject: [Qemu-devel] Re: [PATCH 3/7] AMD IOMMU emulation Date: Sun, 29 Aug 2010 20:37:14 +0000 [thread overview] Message-ID: <AANLkTik-aWPPQ+Gj3TKg6abeahKJAf0-+Yf76+EkhbAx@mail.gmail.com> (raw) In-Reply-To: <20100828215333.GA7270@localhost> On Sat, Aug 28, 2010 at 9:53 PM, Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> wrote: > On Sat, Aug 28, 2010 at 03:58:23PM +0000, Blue Swirl wrote: >> On Sat, Aug 28, 2010 at 2:54 PM, Eduard - Gabriel Munteanu >> <eduard.munteanu@linux360.ro> wrote: >> > This introduces emulation for the AMD IOMMU, described in "AMD I/O >> > Virtualization Technology (IOMMU) Specification". >> > >> > Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> >> > --- > > [snip] > >> > diff --git a/hw/amd_iommu.c b/hw/amd_iommu.c >> > new file mode 100644 >> > index 0000000..43e0426 >> > --- /dev/null >> > +++ b/hw/amd_iommu.c > > [snip] > >> > +static void amd_iommu_update_mmio(AMDIOMMUState *st, >> > + ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ??target_phys_addr_t addr) >> > +{ >> > + ?? ??size_t reg = addr & ~0x07; >> > + ?? ??uint64_t *base = (uint64_t *) &st->mmio_buf[reg]; >> >> This is still buggy. >> >> > + ?? ??uint64_t val = le64_to_cpu(*base); > > mmio_buf is always LE, so a BE host will have *base in reversed > byteorder. But look at the next line, where I did the le64_to_cpu(). > That should swap the bytes on a BE host, yielding the correct byteorder. Sorry, I missed that one when comparing the patch to previous version. > On a LE host, *base is right the first time and le64_to_cpu() is a nop. > > In any case, I only use 'val', not '*base' directly. I suppose it could > be rewritten for clarity (i.e. ditch 'base'). Yes, someone could add more code later which accidentally uses 'base' directly. > Do you still think it's wrong? Or is it for another reason? I think it's OK for now. The rewrite can happen with a small patch later.
next prev parent reply other threads:[~2010-08-29 20:37 UTC|newest] Thread overview: 98+ messages / expand[flat|nested] mbox.gz Atom feed top 2010-08-28 14:54 [PATCH 0/7] AMD IOMMU emulation patchset v4 Eduard - Gabriel Munteanu 2010-08-28 14:54 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-08-28 14:54 ` [PATCH 1/7] pci: expand tabs to spaces in pci_regs.h Eduard - Gabriel Munteanu 2010-08-28 14:54 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-08-31 20:29 ` Michael S. Tsirkin 2010-08-31 20:29 ` [Qemu-devel] " Michael S. Tsirkin 2010-08-31 22:58 ` Eduard - Gabriel Munteanu 2010-08-31 22:58 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-09-01 10:39 ` Michael S. Tsirkin 2010-09-01 10:39 ` [Qemu-devel] " Michael S. Tsirkin 2010-08-28 14:54 ` [PATCH 2/7] pci: memory access API and IOMMU support Eduard - Gabriel Munteanu 2010-08-28 14:54 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-09-02 5:28 ` Michael S. Tsirkin 2010-09-02 5:28 ` [Qemu-devel] " Michael S. Tsirkin 2010-09-02 8:40 ` Eduard - Gabriel Munteanu 2010-09-02 8:40 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-09-02 9:49 ` Michael S. Tsirkin 2010-09-02 9:49 ` [Qemu-devel] " Michael S. Tsirkin 2010-09-04 9:01 ` Blue Swirl 2010-09-04 9:01 ` [Qemu-devel] " Blue Swirl 2010-09-05 7:10 ` Michael S. Tsirkin 2010-09-05 7:10 ` [Qemu-devel] " Michael S. Tsirkin 2010-08-28 14:54 ` [PATCH 3/7] AMD IOMMU emulation Eduard - Gabriel Munteanu 2010-08-28 14:54 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-08-28 15:58 ` Blue Swirl 2010-08-28 15:58 ` [Qemu-devel] " Blue Swirl 2010-08-28 21:53 ` Eduard - Gabriel Munteanu 2010-08-28 21:53 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-08-29 20:37 ` Blue Swirl [this message] 2010-08-29 20:37 ` Blue Swirl 2010-08-30 3:07 ` [Qemu-devel] " Isaku Yamahata 2010-08-30 3:07 ` Isaku Yamahata 2010-08-30 5:54 ` Eduard - Gabriel Munteanu 2010-08-30 5:54 ` Eduard - Gabriel Munteanu 2010-08-28 14:54 ` [PATCH 4/7] ide: use the PCI memory access interface Eduard - Gabriel Munteanu 2010-08-28 14:54 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-09-02 5:19 ` Michael S. Tsirkin 2010-09-02 5:19 ` [Qemu-devel] " Michael S. Tsirkin 2010-09-02 9:12 ` Eduard - Gabriel Munteanu 2010-09-02 9:12 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-09-02 9:58 ` Michael S. Tsirkin 2010-09-02 9:58 ` [Qemu-devel] " Michael S. Tsirkin 2010-09-02 15:01 ` Eduard - Gabriel Munteanu 2010-09-02 15:01 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-09-02 15:24 ` Avi Kivity 2010-09-02 15:24 ` [Qemu-devel] " Avi Kivity 2010-09-02 15:39 ` Michael S. Tsirkin 2010-09-02 15:39 ` [Qemu-devel] " Michael S. Tsirkin 2010-09-02 16:07 ` Avi Kivity 2010-09-02 16:07 ` [Qemu-devel] " Avi Kivity 2010-09-02 15:31 ` Michael S. Tsirkin 2010-09-02 15:31 ` [Qemu-devel] " Michael S. Tsirkin 2010-08-28 14:54 ` [PATCH 5/7] rtl8139: " Eduard - Gabriel Munteanu 2010-08-28 14:54 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-08-28 14:54 ` [PATCH 6/7] eepro100: " Eduard - Gabriel Munteanu 2010-08-28 14:54 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-08-28 14:54 ` [PATCH 7/7] ac97: " Eduard - Gabriel Munteanu 2010-08-28 14:54 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-08-28 16:00 ` [PATCH 0/7] AMD IOMMU emulation patchset v4 Blue Swirl 2010-08-28 16:00 ` [Qemu-devel] " Blue Swirl 2010-08-29 9:55 ` Joerg Roedel 2010-08-29 9:55 ` [Qemu-devel] " Joerg Roedel 2010-08-29 20:44 ` Blue Swirl 2010-08-29 20:44 ` [Qemu-devel] " Blue Swirl 2010-08-29 22:08 ` [PATCH 2/7] pci: memory access API and IOMMU support Eduard - Gabriel Munteanu 2010-08-29 22:08 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-08-29 22:11 ` Eduard - Gabriel Munteanu 2010-08-29 22:11 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-09-01 20:10 ` [Qemu-devel] " Stefan Weil 2010-09-01 20:10 ` Stefan Weil 2010-09-02 6:00 ` Michael S. Tsirkin 2010-09-02 6:00 ` Michael S. Tsirkin 2010-09-02 9:08 ` Eduard - Gabriel Munteanu 2010-09-02 9:08 ` Eduard - Gabriel Munteanu 2010-09-02 13:24 ` Anthony Liguori 2010-09-02 13:24 ` Anthony Liguori 2010-09-02 8:51 ` Eduard - Gabriel Munteanu 2010-09-02 8:51 ` Eduard - Gabriel Munteanu 2010-09-02 16:05 ` Stefan Weil 2010-09-02 16:05 ` Stefan Weil 2010-09-02 16:14 ` Eduard - Gabriel Munteanu 2010-09-02 16:14 ` Eduard - Gabriel Munteanu 2010-09-13 20:01 ` [PATCH RFC] dma_rw.h (was Re: [PATCH 0/7] AMD IOMMU emulation patchset v4) Michael S. Tsirkin 2010-09-13 20:01 ` [Qemu-devel] " Michael S. Tsirkin 2010-09-13 20:45 ` Anthony Liguori 2010-09-13 20:45 ` Anthony Liguori 2010-09-16 7:12 ` Eduard - Gabriel Munteanu 2010-09-16 7:12 ` Eduard - Gabriel Munteanu 2010-09-16 9:35 ` Michael S. Tsirkin 2010-09-16 9:35 ` Michael S. Tsirkin 2010-09-16 7:06 ` Eduard - Gabriel Munteanu 2010-09-16 7:06 ` [Qemu-devel] " Eduard - Gabriel Munteanu 2010-09-16 9:20 ` Michael S. Tsirkin 2010-09-16 9:20 ` [Qemu-devel] " Michael S. Tsirkin 2010-09-16 11:15 ` Eduard - Gabriel Munteanu 2010-09-16 11:15 ` [Qemu-devel] " Eduard - Gabriel Munteanu -- strict thread matches above, loose matches on Subject: below -- 2010-08-15 19:27 [PATCH 0/7] AMD IOMMU emulation patches v3 Eduard - Gabriel Munteanu 2010-08-15 19:27 ` [PATCH 3/7] AMD IOMMU emulation Eduard - Gabriel Munteanu 2010-08-16 17:57 ` Blue Swirl
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