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2013-02-21Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm changes from Peter Anvin: "This is a huge set of several partly interrelated (and concurrently developed) changes, which is why the branch history is messier than one would like. The *really* big items are two humonguous patchsets mostly developed by Yinghai Lu at my request, which completely revamps the way we create initial page tables. In particular, rather than estimating how much memory we will need for page tables and then build them into that memory -- a calculation that has shown to be incredibly fragile -- we now build them (on 64 bits) with the aid of a "pseudo-linear mode" -- a #PF handler which creates temporary page tables on demand. This has several advantages: 1. It makes it much easier to support things that need access to data very early (a followon patchset uses this to load microcode way early in the kernel startup). 2. It allows the kernel and all the kernel data objects to be invoked from above the 4 GB limit. This allows kdump to work on very large systems. 3. It greatly reduces the difference between Xen and native (Xen's equivalent of the #PF handler are the temporary page tables created by the domain builder), eliminating a bunch of fragile hooks. The patch series also gets us a bit closer to W^X. Additional work in this pull is the 64-bit get_user() work which you were also involved with, and a bunch of cleanups/speedups to __phys_addr()/__pa()." * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (105 commits) x86, mm: Move reserving low memory later in initialization x86, doc: Clarify the use of asm("%edx") in uaccess.h x86, mm: Redesign get_user with a __builtin_choose_expr hack x86: Be consistent with data size in getuser.S x86, mm: Use a bitfield to mask nuisance get_user() warnings x86/kvm: Fix compile warning in kvm_register_steal_time() x86-32: Add support for 64bit get_user() x86-32, mm: Remove reference to alloc_remap() x86-32, mm: Remove reference to resume_map_numa_kva() x86-32, mm: Rip out x86_32 NUMA remapping code x86/numa: Use __pa_nodebug() instead x86: Don't panic if can not alloc buffer for swiotlb mm: Add alloc_bootmem_low_pages_nopanic() x86, 64bit, mm: hibernate use generic mapping_init x86, 64bit, mm: Mark data/bss/brk to nx x86: Merge early kernel reserve for 32bit and 64bit x86: Add Crash kernel low reservation x86, kdump: Remove crashkernel range find limit for 64bit memblock: Add memblock_mem_size() x86, boot: Not need to check setup_header version for setup_data ...
2013-02-14lguest: select CONFIG_TTY to build properly.Randy Dunlap
Fix kconfig warning for LGUEST_GUEST config by selecting TTY: warning: (KVMTOOL_TEST_ENABLE && LGUEST_GUEST) selects VIRTIO_CONSOLE which has unmet direct dependencies (VIRTIO && TTY) Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Joe Millenbach <jmillenbach@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-25Merge tag 'v3.8-rc5' into x86/mmH. Peter Anvin
The __pa() fixup series that follows touches KVM code that is not present in the existing branch based on v3.7-rc5, so merge in the current upstream from Linus. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-16x86/lguest: Use __pa_symbol instead of __pa on C visible symbolsAlexander Duyck
The function lguest_write_cr3 is using __pa to convert swapper_pg_dir and initial_page_table from virtual addresses to physical. The correct function to use for these values is __pa_symbol since they are C visible symbols. Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Link: http://lkml.kernel.org/r/20121116215748.8521.83556.stgit@ahduyck-cp1.jf.intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-10-26x86, MCA: Finish mca_config conversionBorislav Petkov
mce_ser, mce_bios_cmci_threshold and mce_disabled are the last three bools which need conversion. Move them to the mca_config struct and adjust usage sites accordingly. Signed-off-by: Borislav Petkov <bp@alien8.de> Acked-by: Tony Luck <tony.luck@intel.com>
2012-09-28virtio: remove CONFIG_VIRTIO_RINGRusty Russell
Everyone who selects VIRTIO is also made to select VIRTIO_RING; just make them synonymous, since we removed the indirection layer some time ago. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-12lguest: Make sure interrupt is allocated ok by lguest_setup_irqStratos Psomadakis
Make sure the interrupt is allocated correctly by lguest_setup_irq (check the return value of irq_alloc_desc_at for -ENOMEM) Signed-off-by: Stratos Psomadakis <psomas@cslab.ece.ntua.gr> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (cleanups and commentry)
2011-10-31lguest: add export.h to lguest files for THIS_MODULE/EXPORT_SYMBOLPaul Gortmaker
We need this in advance of the module.h cleanup, or we'll get compile errors like this: CC drivers/lguest/lguest_device.o drivers/lguest/lguest_device.c: In function ‘lguest_devices_init’: drivers/lguest/lguest_device.c:490: error: ‘THIS_MODULE’ undeclared (first use in this function) Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-27lguest: don't allow KVM-detection cpuid.Rusty Russell
Host might be running under KVM, but we shouldn't allow Guest to think it can use KVM hypercalls (it can't, and it will embarrass itself if it tries). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-07-22lguest: Fix translation count about wikipedia's cpuid pageAdrian Knoth
The comment is outdated, wikipedia now has six translations of the cpuid page. Signed-off-by: Adrian Knoth <adi@drcomp.erfurt.thur.de> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-07-22lguest: Fix three simple typos in commentsAdrian Knoth
This patch fixes three typos I've accidentally spotted. Signed-off-by: Adrian Knoth <adi@drcomp.erfurt.thur.de> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (one was already fixed)
2011-07-22lguest: update commentsRusty Russell
Also removes a long-unused #define and an extraneous semicolon. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-07-22lguest: remove remaining vmcallRusty Russell
We switch back from using vmcall in 091ebf07a2408f9a56634caa0f86d9360e9af23b because it was unreliable under kvm, but I missed one (rarely-used) place. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-07-22lguest: use a special 1:1 linear pagetable mode until first switch.Rusty Russell
The Host used to create some page tables for the Guest to use at the top of Guest memory; it would then tell the Guest where this was. In particular, it created linear mappings for 0 and 0xC0000000 addresses because lguest used to switch to its real page tables quite late in boot. However, since d50d8fe19 Linux initialized boot page tables in head_32.S even before the "are we lguest?" boot jump. So, now we can simplify things: the Host pagetable code assumes 1:1 linear mapping until it first calls the LHCALL_NEW_PGTABLE hypercall, which we now do before we reach C code. This also means that the Host doesn't need to know anything about the Guest's PAGE_OFFSET. (Non-Linux guests might not even have such a thing). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-05-30lguest: fix timer interrupt setupRusty Russell
Without an IRQ chip set, we now get a WARN_ON and no timer interrupt. This prevents booting. Fortunately, the fix is a one-liner: set up the timer IRQ like everything else. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org # .39.x
2011-05-19Merge branch 'timers-clocksource-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-clocksource-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: clocksource: convert mips to generic i8253 clocksource clocksource: convert x86 to generic i8253 clocksource clocksource: convert footbridge to generic i8253 clocksource clocksource: add common i8253 PIT clocksource blackfin: convert to clocksource_register_hz mips: convert to clocksource_register_hz/khz sparc: convert to clocksource_register_hz/khz alpha: convert to clocksource_register_hz microblaze: convert to clocksource_register_hz/khz ia64: convert to clocksource_register_hz/khz x86: Convert remaining x86 clocksources to clocksource_register_hz/khz Make clocksource name const
2011-05-14Merge branch 'consolidate-clksrc-i8253' of ↵Thomas Gleixner
master.kernel.org:~rmk/linux-2.6-arm into timers/clocksource Conflicts: arch/ia64/kernel/cyclone.c arch/mips/kernel/i8253.c arch/x86/kernel/i8253.c Reason: Resolve conflicts so further cleanups do not conflict further Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-05-06Correct occurrences ofRob Landley
- Documentation/kvm/ to Documentation/virtual/kvm - Documentation/uml/ to Documentation/virtual/uml - Documentation/lguest/ to Documentation/virtual/lguest throughout the kernel source tree. Signed-off-by: Rob Landley <rob@landley.net> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
2011-03-18x86: Fix common misspellingsLucas De Marchi
They were generated by 'codespell' and then manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi> Cc: trivial@kernel.org LKML-Reference: <1300389856-1099-3-git-send-email-lucas.demarchi@profusion.mobi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-12x86: Cleanup the genirq name spaceThomas Gleixner
genirq is switching to a consistent name space for the irq related functions. Convert x86. Conversion was done with coccinelle. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-21x86: Convert remaining x86 clocksources to clocksource_register_hz/khzJohn Stultz
This converts the remaining x86 clocksources to use clocksource_register_hz/khz. CC: jacob.jun.pan@intel.com CC: Glauber Costa <glommer@redhat.com> CC: Dimitri Sivanich <sivanich@sgi.com> CC: Rusty Russell <rusty@rustcorp.com.au> CC: Jeremy Fitzhardinge <jeremy@xensource.com> CC: Chris McDermott <lcm@us.ibm.com> CC: Thomas Gleixner <tglx@linutronix.de> Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> [xen] Signed-off-by: John Stultz <johnstul@us.ibm.com>
2011-01-20LGUEST_GUEST: fix unmet direct dependencies (VIRTUALIZATION && VIRTIO)Randy Dunlap
Honor the kconfig menu hierarchy to remove kconfig dependency warnings: VIRTIO and VIRTIO_RING are subordinate to VIRTUALIZATION. warning: (LGUEST_GUEST) selects VIRTIO which has unmet direct dependencies (VIRTUALIZATION) warning: (LGUEST_GUEST && VIRTIO_PCI && VIRTIO_BALLOON) selects VIRTIO_RING which has unmet direct dependencies (VIRTUALIZATION && VIRTIO) Reported-by: Toralf F_rster <toralf.foerster@gmx.de> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-01-20lguest: compile fixesRusty Russell
arch/x86/lguest/boot.c: In function ‘lguest_init_IRQ’: arch/x86/lguest/boot.c:824: error: macro "__this_cpu_write" requires 2 arguments, but only 1 given arch/x86/lguest/boot.c:824: error: ‘__this_cpu_write’ undeclared (first use in this function) arch/x86/lguest/boot.c:824: error: (Each undeclared identifier is reported only once arch/x86/lguest/boot.c:824: error: for each function it appears in.) drivers/lguest/x86/core.c: In function ‘copy_in_guest_info’: drivers/lguest/x86/core.c:94: error: lvalue required as left operand of assignment Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-01-20lguest: Use this_cpu_opsChristoph Lameter
Use this_cpu_ops in a couple of places in lguest. Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-01-04x86, mm: Initialize initial_page_table before paravirt jumpsRusty Russell
v2.6.36-rc8-54-gb40827f (x86-32, mm: Add an initial page table for core bootstrapping) made x86 boot using initial_page_table and broke lguest. For 2.6.37 we simply cut & paste the initialization code into lguest (da32dac10126 "lguest: populate initial_page_table"), now we fix it properly by doing that initialization before the paravirt jump. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Jeremy Fitzhardinge <jeremy@goop.org> Cc: lguest <lguest@ozlabs.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <201101041720.54535.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-16lguest: populate initial_page_tableRusty Russell
Two x86 patches broke lguest: 1) v2.6.35-492-g72d7c3b, which changed x86 to use the memblock allocator. In lguest, the host places linear page tables at the top of mem, which used to be enough to get us up to the swapper_pg_dir page tables. With the first patch, the direct mapping tables used that memory: Before: kernel direct mapping tables up to 4000000 @ 7000-1a000 After: kernel direct mapping tables up to 4000000 @ 3fed000-4000000 I initially fixed this by lying about the amount of memory we had, so the kernel wouldn't blatt the lguest boot pagetables (yuk!), but then... 2) v2.6.36-rc8-54-gb40827f, which made x86 boot use initial_page_table. This was initialized in a part of head_32.S which isn't executed by lguest; it is then copied into swapper_pg_dir. So we have to initialize it; and anyway we switch to it before we blatt the old tables, so that fixes the previous damage as well. For the moment, I cut & pasted the code into lguest's boot code, but next merge window I will merge them. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> To: x86@kernel.org
2010-12-16lguest: restore boot speedRusty Russell
lguest is dumb and drops *all* the pagetables for set_pte (which is only used for kernel mapping manipulation, so it's OK without highmem). But it's used a lot in boot, too. As a guest optimization, we suppressed this flushing until the first page switch. Now we have initial_page_table, that happens much earlier, so extend the heuristic to wait until we switch to something other than the swapper_pg_dir or initial_page_table. As measured on my laptop under kvm, this dropped the time-to-mount-root from 48 seconds to 4.3 seconds. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-12-16lguest: fix crash lguest_time_initRusty Russell
fe25c7fc2e "x86: lguest: Convert to new irq chip functions" converted enable_lguest_irq() to take a struct irq_data *, but didn't fix the one internal caller. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> To: x86@kernel.org
2010-10-12x86: lguest: Use new irq allocatorThomas Gleixner
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu> Cc: Rusty Russell <rusty@rustcorp.com.au>
2010-10-12x86: lguest: Convert to new irq chip functionsThomas Gleixner
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu> Cc: Rusty Russell <rusty@rustcorp.com.au>
2010-09-21lguest: update comments to reflect LHCALL_LOAD_GDT_ENTRY.Rusty Russell
We used to have a hypercall which reloaded the entire GDT, then we switched to one which loaded a single entry (to match the IDT code). Some comments were not updated, so fix them. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Reported by: Eviatar Khen <eviatarkhen@gmail.com>
2010-05-28Merge branch 'ht-delete-2.6.35' into releaseLen Brown
2010-04-14lguest: stop using KVM hypercall mechanismRusty Russell
This is a partial revert of 4cd8b5e2a159 "lguest: use KVM hypercalls"; we revert to using (just as questionable but more reliable) int $15 for hypercalls. I didn't revert the register mapping, so we still use the same calling convention as kvm. KVM in more recent incarnations stopped injecting a fault when a guest tried to use the VMCALL instruction from ring 1, so lguest under kvm fails to make hypercalls. It was nice to share code with our KVM cousins, but this was overreach. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Matias Zabaljauregui <zabaljauregui@gmail.com> Cc: Avi Kivity <avi@redhat.com>
2010-03-14ACPI: delete the "acpi=ht" boot optionLen Brown
acpi=ht was important in 2003 -- before ACPI was universally deployed and enabled by default in the major Linux distributions. At that time, there were a fair number of people who or chose to, or needed to, run with acpi=off, yet also wanted access to Hyper-threading. Today we find that many invocations of "acpi=ht" are accidental, and thus is it possible that it is doing more harm than good. In 2.6.34, we warn on invocation of acpi=ht. In 2.6.35, we delete the boot option. Signed-off-by: Len Brown <len.brown@intel.com>
2009-09-23lguest: move panic notifier registration to its expected place.Rusty Russell
We used to defer it, so lockdep was happy. We now init lockdep early anyway, so just do it after that. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-09-16x86: Move get/set_wallclock to x86_platform_opsFeng Tang
get/set_wallclock() have already a set of platform dependent implementations (default, EFI, paravirt). MRST will add another variant. Moving them to platform ops simplifies the existing code and minimizes the effort to integrate new variants. Signed-off-by: Feng Tang <feng.tang@intel.com> LKML-Reference: <new-submission> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-08-31x86: Move tsc_calibration to x86_init_opsThomas Gleixner
TSC calibration is modified by the vmware hypervisor and paravirt by separate means. Moorestown wants to add its own calibration routine as well. So make calibrate_tsc a proper x86_init_ops function and override it by paravirt or by the early setup of the vmware hypervisor. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-08-31x86: Add timer_init to x86_init_opsThomas Gleixner
The timer init code is convoluted with several quirks and the paravirt timer chooser. Figuring out which code path is actually taken is not for the faint hearted. Move the numaq TSC quirk to tsc_pre_init x86_init_ops function and replace the paravirt time chooser and the remaining x86 quirk with a simple x86_init_ops function. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-08-31x86: Move irq_init to x86_init_opsThomas Gleixner
irq_init is overridden by x86_quirks and by paravirts. Unify the whole mess and make it an unconditional x86_init_ops function which defaults to the standard function and can be overridden by the early platform code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-08-27x86: Move memory_setup to x86_init_opsThomas Gleixner
memory_setup is overridden by x86_quirks and by paravirts with weak functions and quirks. Unify the whole mess and make it an unconditional x86_init_ops function which defaults to the standard function and can be overridden by the early platform code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-07-30lguest: update commentryRusty Russell
Every so often, after code shuffles, I need to go through and unbitrot the Lguest Journey (see drivers/lguest/README). Since we now use RCU in a simple form in one place I took the opportunity to expand that explanation. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@redhat.com> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
2009-07-30lguest: fix comment styleRusty Russell
I don't really notice it (except to begrudge the extra vertical space), but Ingo does. And he pointed out that one excuse of lguest is as a teaching tool, it should set a good example. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@redhat.com>
2009-07-17lguest: restrict CPUID to avoid perf counter wrmsrRusty Russell
Avoid the following: [ 0.012093] WARNING: at arch/x86/kernel/apic/apic.c:249 native_apic_write_dummy+0x2f/0x40() Rather than chase each new cpuid-detected feature, just lie about the highest valid CPUID so this code is never run. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-07-17lguest: fix journeyMatias Zabaljauregui
fix: "make Guest" was complaining about duplicated G:032 Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12lguest: PAE supportMatias Zabaljauregui
This version requires that host and guest have the same PAE status. NX cap is not offered to the guest, yet. Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12lguest: Add support for kvm_hypercall4()Matias Zabaljauregui
Add support for kvm_hypercall4(); PAE wants it. Signed-off-by: Matias Zabaljauregui <zabaljauregui at gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12lguest: replace hypercall name LHCALL_SET_PMD with LHCALL_SET_PGDMatias Zabaljauregui
replace LHCALL_SET_PMD with LHCALL_SET_PGD hypercall name (That's really what it is, and the confusion gets worse with PAE support) Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Reported-by: Jeremy Fitzhardinge <jeremy@goop.org>
2009-06-12lguest: use native_set_* macros, which properly handle 64-bit entries when ↵Matias Zabaljauregui
PAE is activated Some cleanups and replace direct assignment with native_set_* macros which properly handle 64-bit entries when PAE is activated Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12lguest: optimize by coding restore_flags and irq_enable in assembler.Rusty Russell
The downside of the last patch which made restore_flags and irq_enable check interrupts is that they are now too big to be patched directly into the callsites, so the C versions are always used. But the C versions go via PV_CALLEE_SAVE_REGS_THUNK which saves all the registers. In fact, we don't need any registers in the fast path, so we can do better than this if we actually code them in assembler. The results are in the noise, but since it's about the same amount of code, it's worth applying. 1GB Guest->Host: input(suppressed),output(suppressed) Before: Seconds: 0:16.53 Packets: 377268,753673 Interrupts: 22461,24297 Notifications: 1(5245),21303(732370) Net IRQs triggered: 377023(245),42578(711095) After: Seconds: 0:16.48 Packets: 377289,753673 Interrupts: 22281,24465 Notifications: 1(5245),21296(732377) Net IRQs triggered: 377060(229),42564(711109) Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12lguest: improve interrupt handling, speed up stream networkingRusty Russell
lguest never checked for pending interrupts when enabling interrupts, and things still worked. However, it makes a significant difference to TCP performance, so it's time we fixed it by introducing a pending_irq flag and checking it on irq_restore and irq_enable. These two routines are now too big to patch into the 8/10 bytes patch space, so we drop that code. Note: The high latency on interrupt delivery had a very curious effect: once everything else was optimized, networking without GSO was faster than networking with GSO, since more interrupts were sent and hence a greater chance of one getting through to the Guest! Note2: (Almost) Closing the same loophole for iret doesn't have any measurable effect, so I'm leaving that patch for the moment. Before: 1GB tcpblast Guest->Host: 30.7 seconds 1GB tcpblast Guest->Host (no GSO): 76.0 seconds After: 1GB tcpblast Guest->Host: 6.8 seconds 1GB tcpblast Guest->Host (no GSO): 27.8 seconds Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>