From: Paul Brook <paul@codesourcery.com>
To: qemu-devel@nongnu.org
Cc: Richard Henderson <rth@twiddle.net>
Subject: Re: [Qemu-devel] [PATCH 00/35] Alpha system emulation, v4
Date: Tue, 10 May 2011 23:44:49 +0100 [thread overview]
Message-ID: <201105102344.49793.paul@codesourcery.com> (raw)
In-Reply-To: <4DC9B795.2030904@twiddle.net>
> On 05/10/2011 02:33 PM, Paul Brook wrote:
> > There should be nothing special about virtio-pci. These devices should
> > access memory in exactly the same way as any other PCI device. Bypassing
> > the normal PCI iommu is IMO a serious bug.
>
> I suspect that the argument is that virtio is implemented on several
> busses, and ignoring any bus-specific stuff means that there's less
> need for any code differences.
It also has some horrifically bad implications. Not least of which is the
inability to sanely handle nested virtualization.
IMO the whole point of virtio-pci is that it avoids magical weirdness for
virtio devices devices. If you're going to start adding nonstandard
exceptions for virtio devices than there seem little point using PCI in the
first place. It's likely to cause more problems than it solves for the guest
drivers.
Paul
prev parent reply other threads:[~2011-05-10 22:44 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-09 21:34 [Qemu-devel] [PATCH 00/35] Alpha system emulation, v4 Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 01/35] Export the unassigned_mem read/write functions Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 02/35] target-alpha: Disassemble EV6 PALcode instructions Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 03/35] pci: Export pci_to_cpu_addr Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 04/35] target-alpha: Single-step properly across branches Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 05/35] target-alpha: Remove partial support for palcode emulation Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 06/35] target-alpha: Enable the alpha-softmmu target Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 07/35] target-alpha: Tidy exception constants Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 08/35] target-alpha: Rationalize internal processor registers Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 09/35] target-alpha: Cleanup MMU modes Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 10/35] target-alpha: Fixup translation of PALmode instructions Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 11/35] target-alpha: Add IPRs to be used by the emulation PALcode Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 12/35] target-alpha: Tidy up arithmetic exceptions Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 13/35] target-alpha: Use do_restore_state for " Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 14/35] target-alpha: Merge HW_REI and HW_RET implementations Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 15/35] target-alpha: Implement do_interrupt for system mode Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 16/35] target-alpha: Swap shadow registers moving to/from PALmode Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 17/35] target-alpha: Add various symbolic constants Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 18/35] target-alpha: Use kernel mmu_idx for pal_mode Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 19/35] target-alpha: All ISA checks to use TB->FLAGS Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 20/35] target-alpha: Disable interrupts properly Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 21/35] target-alpha: Implement more CALL_PAL values inline Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 22/35] target-alpha: Implement cpu_alpha_handle_mmu_fault for system mode Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 23/35] target-alpha: Remap PIO space for 43-bit KSEG for EV6 Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 24/35] target-alpha: Trap for unassigned and unaligned addresses Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 25/35] target-alpha: Include the PCC_OFS in the RPCC return value Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 26/35] target-alpha: Use a fixed frequency for the RPCC in system mode Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 27/35] target-alpha: Implement TLB flush primitives Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 28/35] target-alpha: Add custom PALcode image for CLIPPER emulation Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 29/35] target-alpha: Add " Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 30/35] target-alpha: Implement WAIT IPR Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 31/35] target-alpha: Implement HALT IPR Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 32/35] target-alpha: Add high-resolution access to wall clock and an alarm Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 33/35] target-alpha: Properly select the VGA controler to use Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 34/35] target-alpha: Enable PCI IDE Richard Henderson
2011-05-09 21:34 ` [Qemu-devel] [PATCH 35/35] target-alpha: Add ps2 keyboard Richard Henderson
2011-05-10 21:33 ` [Qemu-devel] [PATCH 00/35] Alpha system emulation, v4 Paul Brook
2011-05-10 22:09 ` Richard Henderson
2011-05-10 22:44 ` Paul Brook [this message]
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