From: Andrea Arcangeli <aarcange@redhat.com> To: Thiemo Seufer <ths@networkno.de> Cc: qemu-devel@nongnu.org, chrisw@redhat.com, Gerd Hoffmann <kraxel@redhat.com>, kvm@vger.kernel.org Subject: Re: [Qemu-devel] Re: [PATCH 2 of 5] add can_dma/post_dma for direct IO Date: Tue, 23 Dec 2008 02:02:36 +0100 [thread overview] Message-ID: <20081223010236.GI27662@random.random> (raw) In-Reply-To: <20081223000336.GB16266@networkno.de> On Tue, Dec 23, 2008 at 01:03:36AM +0100, Thiemo Seufer wrote: > Running x86-64 binaries on a (non-x86) 32-bit host is IMHO quite an > obvious application for qemu/tcg. I doubt you need device drivers when only translating bytecode. DMA API discussed here is an API for drivers only AFIK. > Interestingly, Virtualbox just started to support > 64-bit-target-on-32-bit-host. Yes, and KVM supports this already AFIK (without PR and without any dynamic map/unmap operation that doesn't exist today). The issue here is not to run 64bit target on 32bit host, this is about running a 64bit target with >3G (or >4G of ram perhaps on sparc32 that has separate kernel/user address space) of ram on a 32bit host. What we're discussing here is a new feature. It's hard to imagine any not-x86 32bit system, to want to run a >3G ram x86-64 (or any other 64bit) VM. It wouldn't work today, and I'm not particularly interested to make it work in 2009 and later given it's 99.9% more likely that you have a 64bit capable CPU than >4G of ram on your system. The limit isn't the size of the guest physical address space, the limit is the amount of RAM that you want to give to the 64bit guest.
WARNING: multiple messages have this Message-ID (diff)
From: Andrea Arcangeli <aarcange@redhat.com> To: Thiemo Seufer <ths@networkno.de> Cc: chrisw@redhat.com, qemu-devel@nongnu.org, kvm@vger.kernel.org, Gerd Hoffmann <kraxel@redhat.com> Subject: Re: [Qemu-devel] Re: [PATCH 2 of 5] add can_dma/post_dma for direct IO Date: Tue, 23 Dec 2008 02:02:36 +0100 [thread overview] Message-ID: <20081223010236.GI27662@random.random> (raw) In-Reply-To: <20081223000336.GB16266@networkno.de> On Tue, Dec 23, 2008 at 01:03:36AM +0100, Thiemo Seufer wrote: > Running x86-64 binaries on a (non-x86) 32-bit host is IMHO quite an > obvious application for qemu/tcg. I doubt you need device drivers when only translating bytecode. DMA API discussed here is an API for drivers only AFIK. > Interestingly, Virtualbox just started to support > 64-bit-target-on-32-bit-host. Yes, and KVM supports this already AFIK (without PR and without any dynamic map/unmap operation that doesn't exist today). The issue here is not to run 64bit target on 32bit host, this is about running a 64bit target with >3G (or >4G of ram perhaps on sparc32 that has separate kernel/user address space) of ram on a 32bit host. What we're discussing here is a new feature. It's hard to imagine any not-x86 32bit system, to want to run a >3G ram x86-64 (or any other 64bit) VM. It wouldn't work today, and I'm not particularly interested to make it work in 2009 and later given it's 99.9% more likely that you have a 64bit capable CPU than >4G of ram on your system. The limit isn't the size of the guest physical address space, the limit is the amount of RAM that you want to give to the 64bit guest.
next prev parent reply other threads:[~2008-12-23 1:02 UTC|newest] Thread overview: 111+ messages / expand[flat|nested] mbox.gz Atom feed top 2008-12-12 18:16 [PATCH 0 of 5] dma api v3 Andrea Arcangeli 2008-12-12 18:16 ` [Qemu-devel] " Andrea Arcangeli 2008-12-12 18:16 ` [PATCH 1 of 5] fix cpu_physical_memory len Andrea Arcangeli 2008-12-12 18:16 ` [Qemu-devel] " Andrea Arcangeli 2008-12-12 19:06 ` Anthony Liguori 2008-12-12 19:06 ` [Qemu-devel] " Anthony Liguori 2008-12-12 19:26 ` Andrea Arcangeli 2008-12-12 19:26 ` [Qemu-devel] " Andrea Arcangeli 2008-12-12 18:16 ` [PATCH 2 of 5] add can_dma/post_dma for direct IO Andrea Arcangeli 2008-12-12 18:16 ` [Qemu-devel] " Andrea Arcangeli 2008-12-12 19:00 ` Blue Swirl 2008-12-12 19:00 ` Blue Swirl 2008-12-12 19:18 ` Anthony Liguori 2008-12-12 19:18 ` Anthony Liguori 2008-12-12 20:05 ` Blue Swirl 2008-12-12 20:10 ` Anthony Liguori 2008-12-12 20:10 ` Anthony Liguori 2008-12-12 19:15 ` Anthony Liguori 2008-12-12 19:15 ` [Qemu-devel] " Anthony Liguori 2008-12-12 19:37 ` Andrea Arcangeli 2008-12-12 19:37 ` [Qemu-devel] " Andrea Arcangeli 2008-12-12 20:09 ` Anthony Liguori 2008-12-12 20:09 ` [Qemu-devel] " Anthony Liguori 2008-12-12 20:25 ` Gerd Hoffmann 2008-12-12 20:25 ` [Qemu-devel] " Gerd Hoffmann 2008-12-12 19:39 ` Anthony Liguori 2008-12-12 19:39 ` [Qemu-devel] " Anthony Liguori 2008-12-13 9:22 ` Avi Kivity 2008-12-13 9:22 ` Avi Kivity 2008-12-13 16:45 ` Anthony Liguori 2008-12-13 16:45 ` Anthony Liguori 2008-12-13 19:48 ` Avi Kivity 2008-12-13 19:48 ` Avi Kivity 2008-12-13 21:07 ` Anthony Liguori 2008-12-13 21:07 ` Anthony Liguori 2008-12-14 6:03 ` Avi Kivity 2008-12-14 6:03 ` Avi Kivity 2008-12-14 19:10 ` Anthony Liguori 2008-12-14 19:10 ` Anthony Liguori 2008-12-14 19:49 ` Avi Kivity 2008-12-14 19:49 ` Avi Kivity 2008-12-14 23:08 ` Anthony Liguori 2008-12-14 23:08 ` Anthony Liguori 2008-12-15 0:57 ` Paul Brook 2008-12-15 0:57 ` Paul Brook 2008-12-15 2:09 ` Anthony Liguori 2008-12-15 2:09 ` Anthony Liguori 2008-12-15 6:23 ` Avi Kivity 2008-12-15 6:23 ` Avi Kivity 2008-12-15 18:35 ` Blue Swirl 2008-12-15 18:35 ` Blue Swirl 2008-12-15 22:06 ` Anthony Liguori 2008-12-15 22:06 ` Anthony Liguori 2008-12-16 9:41 ` Avi Kivity 2008-12-16 9:41 ` Avi Kivity 2008-12-16 16:55 ` Blue Swirl 2008-12-16 16:55 ` Blue Swirl 2008-12-16 17:09 ` Avi Kivity 2008-12-16 17:09 ` Avi Kivity 2008-12-16 17:48 ` Anthony Liguori 2008-12-16 17:48 ` Anthony Liguori 2008-12-16 18:11 ` Blue Swirl 2008-12-16 18:11 ` Blue Swirl 2008-12-16 15:57 ` Blue Swirl 2008-12-16 15:57 ` Blue Swirl 2008-12-16 16:29 ` Paul Brook 2008-12-16 16:29 ` Paul Brook 2008-12-16 16:35 ` Blue Swirl 2008-12-16 16:35 ` Blue Swirl 2008-12-14 17:30 ` Jamie Lokier 2008-12-14 17:30 ` Jamie Lokier 2008-12-13 14:39 ` Andrea Arcangeli 2008-12-13 14:39 ` [Qemu-devel] " Andrea Arcangeli 2008-12-13 16:46 ` Anthony Liguori 2008-12-13 16:46 ` [Qemu-devel] " Anthony Liguori 2008-12-13 16:53 ` Andrea Arcangeli 2008-12-13 16:53 ` [Qemu-devel] " Andrea Arcangeli 2008-12-13 17:54 ` Andreas Färber 2008-12-13 21:11 ` Anthony Liguori 2008-12-13 21:11 ` [Qemu-devel] " Anthony Liguori 2008-12-14 16:47 ` Andrea Arcangeli 2008-12-14 16:47 ` [Qemu-devel] " Andrea Arcangeli 2008-12-14 17:01 ` Avi Kivity 2008-12-14 17:01 ` [Qemu-devel] " Avi Kivity 2008-12-14 17:15 ` Andrea Arcangeli 2008-12-14 17:15 ` [Qemu-devel] " Andrea Arcangeli 2008-12-14 19:59 ` Avi Kivity 2008-12-14 19:59 ` [Qemu-devel] " Avi Kivity 2008-12-22 16:44 ` Ian Jackson 2008-12-22 16:44 ` Ian Jackson 2008-12-22 19:44 ` Avi Kivity 2008-12-23 0:03 ` Thiemo Seufer 2008-12-23 1:02 ` Andrea Arcangeli [this message] 2008-12-23 1:02 ` Andrea Arcangeli 2008-12-23 17:31 ` Avi Kivity 2008-12-23 17:31 ` Avi Kivity 2008-12-22 19:46 ` Avi Kivity 2009-01-05 10:27 ` Gerd Hoffmann 2009-01-05 10:27 ` Gerd Hoffmann 2008-12-13 22:47 ` Anthony Liguori 2008-12-13 22:47 ` [Qemu-devel] " Anthony Liguori 2008-12-14 6:07 ` Avi Kivity 2008-12-14 6:07 ` [Qemu-devel] " Avi Kivity 2008-12-12 18:16 ` [PATCH 3 of 5] rename dma.c to isa_dma.c Andrea Arcangeli 2008-12-12 18:16 ` [Qemu-devel] " Andrea Arcangeli 2008-12-12 18:16 ` [PATCH 4 of 5] dma api Andrea Arcangeli 2008-12-12 18:16 ` [Qemu-devel] " Andrea Arcangeli 2008-12-12 18:55 ` Blue Swirl 2008-12-12 18:55 ` Blue Swirl 2008-12-12 18:16 ` [PATCH 5 of 5] bdrv_aio_readv/writev Andrea Arcangeli 2008-12-12 18:16 ` [Qemu-devel] " Andrea Arcangeli
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20081223010236.GI27662@random.random \ --to=aarcange@redhat.com \ --cc=chrisw@redhat.com \ --cc=kraxel@redhat.com \ --cc=kvm@vger.kernel.org \ --cc=qemu-devel@nongnu.org \ --cc=ths@networkno.de \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.