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* xen: fix pinning when not using split pte locksJeremy Fitzhardinge2008-09-101-2/+2
| | | | | | | | We only pin PTE pages when using split PTE locks, so don't do the pin/unpin when attaching/detaching pte pages to a pinned pagetable. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'core/xen' into x86/xenIngo Molnar2008-09-101-1/+1
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| * mm: define USE_SPLIT_PTLOCKS rather than repeating expressionJeremy Fitzhardinge2008-09-101-1/+1
| | | | | | | | | | | | | | | | | | Define USE_SPLIT_PTLOCKS as a constant expression rather than repeating "NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS" all over the place. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * x86, xen: Use native_pte_flags instead of native_pte_val for .pte_flagsEduardo Habkost2008-09-061-1/+1
| | | | | | | | | | | | | | | | | | Using native_pte_val triggers the BUG_ON() in the paravirt_ops version of pte_flags(). Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | xen: make CPU hotplug functions staticAlex Nixon2008-09-082-10/+6
| | | | | | | | | | | | | | | | There's no need for these functions to be accessed from outside of xen/smp.c Signed-off-by: Alex Nixon <alex.nixon@citrix.com> Acked-by: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | x86, xen: fix build when !CONFIG_HOTPLUG_CPUAlex Nixon2008-09-081-0/+18
| | | | | | | | | | | | Signed-off-by: Alex Nixon <alex.nixon@citrix.com> Acked-by: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | xen: implement CPU hotpluggingAlex Nixon2008-08-254-12/+67
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Note the changes from 2.6.18-xen CPU hotplugging: A vcpu_down request from the remote admin via Xenbus both hotunplugs the CPU, and disables it by removing it from the cpu_present map, and removing its entry in /sys. A vcpu_up request from the remote admin only re-enables the CPU, and does not immediately bring the CPU up. A udev event is emitted, which can be caught by the user if he wishes to automatically re-up CPUs when available, or implement a more complex policy. Signed-off-by: Alex Nixon <alex.nixon@citrix.com> Acked-by: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | x86: build fix in "xen spinlock updates and performance measurements"Jeremy Fitzhardinge2008-08-222-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ingo Molnar wrote: > -tip testing found this build failure: > > arch/x86/xen/spinlock.c: In function ‘spin_time_start’: > arch/x86/xen/spinlock.c:60: error: implicit declaration of function ‘xen_clocksource_read’ > > i've excluded these new commits for now from tip/master - could you > please send a delta fix against tip/x86/xen? Make xen_clocksource_read non-static. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | xen: measure how long spinlocks spend blockingJeremy Fitzhardinge2008-08-211-20/+42
| | | | | | | | | | | | | | | | | | Measure how long spinlocks spend blocked. Also rename some fields to be more consistent. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | xen: allow interrupts to be enabled while doing a blocking spinJeremy Fitzhardinge2008-08-211-3/+27
| | | | | | | | | | | | | | | | | | | | | | If spin_lock is called in an interrupts-enabled context, we can safely enable interrupts while spinning. We don't bother for the actual spin loop, but if we timeout and fall back to blocking, it's definitely worthwhile enabling interrupts if possible. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | xen: add debugfs supportJeremy Fitzhardinge2008-08-217-9/+580
| | | | | | | | | | | | | | | | | | | | | | | | | | Add support for exporting statistics on mmu updates, multicall batching and pv spinlocks into debugfs. The base path is xen/ and each subsystem adds its own directory: mmu, multicalls, spinlocks. In each directory, writing 1 to "zero_stats" will cause the corresponding stats to be zeroed the next time they're updated. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | xen: save previous spinlock when blockingJeremy Fitzhardinge2008-08-211-15/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A spinlock can be interrupted while spinning, so make sure we preserve the previous lock of interest if we're taking a lock from within an interrupt handler. We also need to deal with the case where the blocking path gets interrupted between testing to see if the lock is free and actually blocking. If we get interrupted there and end up in the state where the lock is free but the irq isn't pending, then we'll block indefinitely in the hypervisor. This fix is to make sure that any nested lock-takers will always leave the irq pending if there's any chance the outer lock became free. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | xen: add xen_ prefixes to make tracing with ftrace easierJeremy Fitzhardinge2008-08-201-32/+34
| | | | | | | | | | | | | | It's easier to pattern match on Xen function if they all start with xen_. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | xen: clarify locking used when pinning a pagetable.Jeremy Fitzhardinge2008-08-201-6/+35
| | | | | | | | | | | | | | | | | | | | Add some comments explaining the locking and pinning algorithm when using split pte locks. Also implement a minor optimisation of not pinning the PTE when not using split pte locks. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Xen-devel <xen-devel@lists.xensource.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | xen: clean up domain mode predicatesJeremy Fitzhardinge2008-08-201-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | There are four operating modes Xen code may find itself running in: - native - hvm domain - pv dom0 - pv domU Clean up predicates for testing for these states to make them more consistent. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Xen-devel <xen-devel@lists.xensource.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | xen_alloc_ptpage: cast PFN_PHYS() argument to unsigned longEduardo Habkost2008-07-311-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently paravirt_ops alloc_p*() uses u32 for the pfn args. We should change that later, but while the pfn parameter is still u32, we need to cast the PFN_PHYS() argument at xen_alloc_ptpage() to unsigned long, otherwise it will lose bits on the shift. I think PFN_PHYS() should behave better when fed with smaller integers, but a cast to unsigned long won't be enough for all cases on 32-bit PAE, and a cast to u64 would be overkill for most users of PFN_PHYS(). We could have two different flavors of PFN_PHYS: one for low pages only (unsigned long) and another that works for any page (u64)), but while we don't have it, we will need the cast to unsigned long on xen_alloc_ptpage(). Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | xen: fix allocation and use of large ldts, cleanupJeremy Fitzhardinge2008-07-311-4/+5
| | | | | | | | | | | | | | | | Add a proper comment for set_aliased_prot() and fix an unsigned long/void * warning. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | xen: compile irq functions without -pg for ftraceJeremy Fitzhardinge2008-07-316-123/+150
| | | | | | | | | | | | | | | | | | | | | | | | | | For some reason I managed to miss a bunch of irq-related functions which also need to be compiled without -pg when using ftrace. This patch moves them into their own file, and starts a cleanup process I've been meaning to do anyway. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: "Alex Nixon (Intern)" <Alex.Nixon@eu.citrix.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Merge branch 'x86/spinlocks' into x86/xenIngo Molnar2008-07-314-168/+193
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| * | x86: split spinlock implementations out into their own filesJeremy Fitzhardinge2008-07-244-168/+193
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ftrace requires certain low-level code, like spinlocks and timestamps, to be compiled without -pg in order to avoid infinite recursion. This patch splits out the core paravirt spinlocks and the Xen spinlocks into separate files which can be compiled without -pg. Also do xen/time.c while we're about it. As a result, we can now use ftrace within a Xen domain. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | xen: suppress known wrmsrsJeremy Fitzhardinge2008-07-281-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In general, Xen doesn't support wrmsr from an unprivileged domain; it just ends up ignoring the instruction and printing a message on the console. Given that there are sets of MSRs we know the kernel will try to write to, but we don't care, just eat them in xen_write_msr to cut down on console noise. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | xen: fix allocation and use of large ldtsJeremy Fitzhardinge2008-07-281-10/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the ldt gets to more than 1 page in size, the kernel uses vmalloc to allocate it. This means that: - when making the ldt RO, we must update the pages in both the vmalloc mapping and the linear mapping to make sure there are no RW aliases. - we need to use arbitrary_virt_to_machine to compute the machine addr for each update Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | x86, xen: Use native_pte_flags instead of native_pte_val for .pte_flagsEduardo Habkost2008-07-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | Using native_pte_val triggers the BUG_ON() in the paravirt_ops version of pte_flags(). Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | Merge branch 'linus' into x86/xenIngo Molnar2008-07-261-1/+1
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| * | xen: don't use sysret for sysexit32Jeremy Fitzhardinge2008-07-241-1/+1
| |/ | | | | | | | | | | | | | | | | | | When implementing sysexit32, don't let Xen use sysret to return to userspace. That results in usermode register state being trashed. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Mark McLoughlin <markmc@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* / x86/paravirt/xen: properly fill out the ldt opsJeremy Fitzhardinge2008-07-241-0/+23
|/ | | | | | | | | LTP testing showed that Xen does not properly implement sys_modify_ldt(). This patch does the final little bits needed to make the ldt work properly. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'cpus4096-for-linus' of ↵Linus Torvalds2008-07-231-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'cpus4096-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (31 commits) NR_CPUS: Replace NR_CPUS in speedstep-centrino.c cpumask: Provide a generic set of CPUMASK_ALLOC macros, FIXUP NR_CPUS: Replace NR_CPUS in cpufreq userspace routines NR_CPUS: Replace per_cpu(..., smp_processor_id()) with __get_cpu_var NR_CPUS: Replace NR_CPUS in arch/x86/kernel/genapic_flat_64.c NR_CPUS: Replace NR_CPUS in arch/x86/kernel/genx2apic_uv_x.c NR_CPUS: Replace NR_CPUS in arch/x86/kernel/cpu/proc.c NR_CPUS: Replace NR_CPUS in arch/x86/kernel/cpu/mcheck/mce_64.c cpumask: Optimize cpumask_of_cpu in lib/smp_processor_id.c, fix cpumask: Use optimized CPUMASK_ALLOC macros in the centrino_target cpumask: Provide a generic set of CPUMASK_ALLOC macros cpumask: Optimize cpumask_of_cpu in lib/smp_processor_id.c cpumask: Optimize cpumask_of_cpu in kernel/time/tick-common.c cpumask: Optimize cpumask_of_cpu in drivers/misc/sgi-xp/xpc_main.c cpumask: Optimize cpumask_of_cpu in arch/x86/kernel/ldt.c cpumask: Optimize cpumask_of_cpu in arch/x86/kernel/io_apic_64.c cpumask: Replace cpumask_of_cpu with cpumask_of_cpu_ptr Revert "cpumask: introduce new APIs" cpumask: make for_each_cpu_mask a bit smaller net: Pass reference to cpumask variable in net/sunrpc/svc.c ... Fix up trivial conflicts in drivers/cpufreq/cpufreq.c manually
| * Merge branch 'linus' into cpus4096Ingo Molnar2008-07-1614-303/+628
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/x86/xen/smp.c kernel/sched_rt.c net/iucv/iucv.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * \ Merge commit 'v2.6.26-rc9' into cpus4096Ingo Molnar2008-07-066-231/+80
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| * | | x86: use performance variant for_each_cpu_mask_nrMike Travis2008-05-231-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change references from for_each_cpu_mask to for_each_cpu_mask_nr where appropriate Reviewed-by: Paul Jackson <pj@sgi.com> Reviewed-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> commit 2d474871e2fb092eb46a0930aba5442e10eb96cc Author: Mike Travis <travis@sgi.com> Date: Mon May 12 21:21:13 2008 +0200
* | | | x86: add PTE_FLAGS_MASKJeremy Fitzhardinge2008-07-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PTE_PFN_MASK was getting lonely, so I made it a friend. Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | x86: rename PTE_MASK to PTE_PFN_MASKJeremy Fitzhardinge2008-07-222-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rusty, in his peevish way, complained that macros defining constants should have a name which somewhat accurately reflects the actual purpose of the constant. Aside from the fact that PTE_MASK gives no clue as to what's actually being masked, and is misleadingly similar to the functionally entirely different PMD_MASK, PUD_MASK and PGD_MASK, I don't really see what the problem is. But if this patch silences the incessent noise, then it will have achieved its goal (TODO: write test-case). Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | Merge branch 'x86/paravirt-spinlocks' into x86/for-linusIngo Molnar2008-07-211-0/+171
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| * | | | xen: implement Xen-specific spinlocksJeremy Fitzhardinge2008-07-161-1/+171
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The standard ticket spinlocks are very expensive in a virtual environment, because their performance depends on Xen's scheduler giving vcpus time in the order that they're supposed to take the spinlock. This implements a Xen-specific spinlock, which should be much more efficient. The fast-path is essentially the old Linux-x86 locks, using a single lock byte. The locker decrements the byte; if the result is 0, then they have the lock. If the lock is negative, then locker must spin until the lock is positive again. When there's contention, the locker spin for 2^16[*] iterations waiting to get the lock. If it fails to get the lock in that time, it adds itself to the contention count in the lock and blocks on a per-cpu event channel. When unlocking the spinlock, the locker looks to see if there's anyone blocked waiting for the lock by checking for a non-zero waiter count. If there's a waiter, it traverses the per-cpu "lock_spinners" variable, which contains which lock each CPU is waiting on. It picks one CPU waiting on the lock and sends it an event to wake it up. This allows efficient fast-path spinlock operation, while allowing spinning vcpus to give up their processor time while waiting for a contended lock. [*] 2^16 iterations is threshold at which 98% locks have been taken according to Thomas Friebel's Xen Summit talk "Preventing Guests from Spinning Around". Therefore, we'd expect the lock and unlock slow paths will only be entered 2% of the time. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Lameter <clameter@linux-foundation.org> Cc: Petr Tesarik <ptesarik@suse.cz> Cc: Virtualization <virtualization@lists.linux-foundation.org> Cc: Xen devel <xen-devel@lists.xensource.com> Cc: Thomas Friebel <thomas.friebel@amd.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | xen: use lock-byte spinlock implementationJeremy Fitzhardinge2008-07-161-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Switch to using the lock-byte spinlock implementation, to avoid the worst of the performance hit from ticket locks. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Lameter <clameter@linux-foundation.org> Cc: Petr Tesarik <ptesarik@suse.cz> Cc: Virtualization <virtualization@lists.linux-foundation.org> Cc: Xen devel <xen-devel@lists.xensource.com> Cc: Thomas Friebel <thomas.friebel@amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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*-------. \ \ \ \ Merge branches 'x86/urgent', 'x86/amd-iommu', 'x86/apic', 'x86/cleanups', ↵Ingo Molnar2008-07-2113-345/+1255
|\ \ \ \ \ \ \ \ \ | |_|_|_|_|_|_|_|/ |/| | | | | | | | | | | | | | | | | 'x86/core', 'x86/cpu', 'x86/fixmap', 'x86/gart', 'x86/kprobes', 'x86/memtest', 'x86/modules', 'x86/nmi', 'x86/pat', 'x86/reboot', 'x86/setup', 'x86/step', 'x86/unify-pci', 'x86/uv', 'x86/xen' and 'xen-64bit' into x86/for-linus
| | | | | * | | | x86, xen, power: fix up config dependencies on PMJeremy Fitzhardinge2008-07-171-0/+5
| | | | | |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Xen save/restore needs bits of code enabled by PM_SLEEP, and PM_SLEEP depends on PM. So make XEN_SAVE_RESTORE depend on PM and PM_SLEEP depend on XEN_SAVE_RESTORE. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | | | * | | x86: xen: no need to disable vdso32Jeremy Fitzhardinge2008-07-161-7/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the vdso32 code can cope with both syscall and sysenter missing for 32-bit compat processes, just disable the features without disabling vdso altogether. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| | | | | * | | x86_64: further cleanup of 32-bit compat syscall mechanismsJeremy Fitzhardinge2008-07-161-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | AMD only supports "syscall" from 32-bit compat usermode. Intel and Centaur(?) only support "sysenter" from 32-bit compat usermode. Set the X86 feature bits accordingly, and set up the vdso in accordance with those bits. On the offchance we run on in a 64-bit environment which supports neither syscall nor sysenter from 32-bit mode, then fall back to the int $0x80 vdso. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| | | | | * | | x86, xen, vdso: fix build errorIngo Molnar2008-07-161-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fix: arch/x86/xen/built-in.o: In function `xen_enable_syscall': (.cpuinit.text+0xdb): undefined reference to `sysctl_vsyscall32' Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | | | * | | xen64: disable 32-bit syscall/sysenter if not supported.Jeremy Fitzhardinge2008-07-161-19/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Old versions of Xen (3.1 and before) don't support sysenter or syscall from 32-bit compat userspaces. If we can't set the appropriate syscall callback, then disable the corresponding feature bit, which will cause the vdso32 setup to fall back appropriately. Linux assumes that syscall is always available to 32-bit userspace, and installs it by default if sysenter isn't available. In that case, we just disable vdso altogether, forcing userspace libc to fall back to int $0x80. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | | | * | | xen64: fix build error on 32-bit + !HIGHMEMIngo Molnar2008-07-161-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fix: arch/x86/xen/enlighten.c: In function 'xen_set_fixmap': arch/x86/xen/enlighten.c:1127: error: 'FIX_KMAP_BEGIN' undeclared (first use in this function) arch/x86/xen/enlighten.c:1127: error: (Each undeclared identifier is reported only once arch/x86/xen/enlighten.c:1127: error: for each function it appears in.) arch/x86/xen/enlighten.c:1127: error: 'FIX_KMAP_END' undeclared (first use in this function) make[1]: *** [arch/x86/xen/enlighten.o] Error 1 make: *** [arch/x86/xen/enlighten.o] Error 2 FIX_KMAP_BEGIN is only available on HIGHMEM. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | | | * | | xen: update Kconfig to allow 64-bit XenJeremy Fitzhardinge2008-07-161-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow Xen to be enabled on 64-bit. Also extend domain size limit from 8 GB (on 32-bit) to 32 GB on 64-bit. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | | | * | | xen: implement Xen write_msr operationJeremy Fitzhardinge2008-07-161-1/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 64-bit uses MSRs for important things like the base for fs and gs-prefixed addresses. It's more efficient to use a hypercall to update these, rather than go via the trap and emulate path. Other MSR writes are just passed through; in an unprivileged domain they do nothing, but it might be useful later. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | | | * | | xen64: set up userspace syscall patchJeremy Fitzhardinge2008-07-161-10/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 64-bit userspace expects the vdso to be mapped at a specific fixed address, which happens to be in the middle of the kernel address space. Because we have split user and kernel pagetables, we need to make special arrangements for the vsyscall mapping to appear in the kernel part of the user pagetable. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | | | * | | xen64: set up syscall and sysenter entrypoints for 64-bitJeremy Fitzhardinge2008-07-165-5/+174
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We set up entrypoints for syscall and sysenter. sysenter is only used for 32-bit compat processes, whereas syscall can be used in by both 32 and 64-bit processes. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | | | * | | xen64: allocate and manage user pagetablesJeremy Fitzhardinge2008-07-163-24/+168
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Because the x86_64 architecture does not enforce segment limits, Xen cannot protect itself with them as it does in 32-bit mode. Therefore, to protect itself, it runs the guest kernel in ring 3. Since it also runs the guest userspace in ring3, the guest kernel must maintain a second pagetable for its userspace, which does not map kernel space. Naturally, the guest kernel pagetables map both kernel and userspace. The userspace pagetable is attached to the corresponding kernel pagetable via the pgd's page->private field. It is allocated and freed at the same time as the kernel pgd via the paravirt_pgd_alloc/free hooks. Fortunately, the user pagetable is almost entirely shared with the kernel pagetable; the only difference is the pgd page itself. set_pgd will populate all entries in the kernel pagetable, and also set the corresponding user pgd entry if the address is less than STACK_TOP_MAX. The user pagetable must be pinned and unpinned with the kernel one, but because the pagetables are aliased, pgd_walk() only needs to be called on the kernel pagetable. The user pgd page is then pinned/unpinned along with the kernel pgd page. xen_write_cr3 must write both the kernel and user cr3s. The init_mm.pgd pagetable never has a user pagetable allocated for it, because it can never be used while running usermode. One awkward area is that early in boot the page structures are not available. No user pagetable can exist at that point, but it complicates the logic to avoid looking at the page structure. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | | | * | | xen64: Clear %fs on xen_load_tls()Eduardo Habkost2008-07-161-9/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We need to do this, otherwise we can get a GPF on hypercall return after TLS descriptor is cleared but %fs is still pointing to it. Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | | | * | | xen: make sure the kernel command line is rightJeremy Fitzhardinge2008-07-161-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Point the boot params cmd_line_ptr to the domain-builder-provided command line. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | | | * | | xen: rework pgd_walk to deal with 32/64 bitJeremy Fitzhardinge2008-07-161-40/+75
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rewrite pgd_walk to deal with 64-bit address spaces. There are two notible features of 64-bit workspaces: 1. The physical address is only 48 bits wide, with the upper 16 bits being sign extension; kernel addresses are negative, and userspace is positive. 2. The Xen hypervisor mapping is at the negative-most address, just above the sign-extension hole. 1. means that we can't easily use addresses when traversing the space, since we must deal with sign extension. This rewrite expresses everything in terms of pgd/pud/pmd indices, which means we don't need to worry about the exact configuration of the virtual memory space. This approach works equally well in 32-bit. To deal with 2, assume the hole is between the uppermost userspace address and PAGE_OFFSET. For 64-bit this skips the Xen mapping hole. For 32-bit, the hole is zero-sized. In all cases, the uppermost kernel address is FIXADDR_TOP. A side-effect of this patch is that the upper boundary is actually handled properly, exposing a long-standing bug in 32-bit, which failed to pin kernel pmd page. The kernel pmd is not shared, and so must be explicitly pinned, even though the kernel ptes are shared and don't need pinning. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>