- 30 1月, 2008 15 次提交
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This patch adjust the paravirt macros used in assembly code to accomodate for x86_64 as well. Signed-off-by: NGlauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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To account for differences in x86_64, we change the macros that create raw instances of the paravirt_patch_site struct. We need to align 64-pointers to 64-bit boundaries, so we add an alignment directive. Also, we need to make room for a word-sized pointer, instead of a fixed 32-bit one Signed-off-by: NGlauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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This patch adds a field in pv_cpu_ops for a paravirtualized hook for rdtscp, needed for x86_64. Signed-off-by: NGlauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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write_tsc() does not need to be enclosed in any paravirt closure, as it uses wrmsr(). So we rip off the duplicate in msr.h and the definition from paravirt.h Signed-off-by: NGlauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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This patch adjust the PVOP_VCALL and PVOP_CALL macros to work with x86_64. It has a different calling convention, and we use auxiliary macros to account for both calling conventions as cleanly as possible Comments are adjusted accordingly. Signed-off-by: NGlauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Nick Piggin 提交于
Introduce ticket lock spinlocks for x86 which are FIFO. The implementation is described in the comments. The straight-line lock/unlock instruction sequence is slightly slower than the dec based locks on modern x86 CPUs, however the difference is quite small on Core2 and Opteron when working out of cache, and becomes almost insignificant even on P4 when the lock misses cache. trylock is more significantly slower, but they are relatively rare. On an 8 core (2 socket) Opteron, spinlock unfairness is extremely noticable, with a userspace test having a difference of up to 2x runtime per thread, and some threads are starved or "unfairly" granted the lock up to 1 000 000 (!) times. After this patch, all threads appear to finish at exactly the same time. The memory ordering of the lock does conform to x86 standards, and the implementation has been reviewed by Intel and AMD engineers. The algorithm also tells us how many CPUs are contending the lock, so lockbreak becomes trivial and we no longer have to waste 4 bytes per spinlock for it. After this, we can no longer spin on any locks with preempt enabled and cannot reenable interrupts when spinning on an irq safe lock, because at that point we have already taken a ticket and the would deadlock if the same CPU tries to take the lock again. These are questionable anyway: if the lock happens to be called under a preempt or interrupt disabled section, then it will just have the same latency problems. The real fix is to keep critical sections short, and ensure locks are reasonably fair (which this patch does). Signed-off-by: NNick Piggin <npiggin@suse.de> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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this patch changes the signature of write_ldt_entry. Signed-off-by: NGlauber de Oliveira Costa <gcosta@redhat.com> CC: Zachary Amsden <zach@vmware.com> CC: Jeremy Fitzhardinge <Jeremy.Fitzhardinge.citrix.com> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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This patch changes the write_gdt_entry function signature. Instead of the old "a" and "b" parameters, it now receives a pointer to a desc_struct, and the size of the entry being handled. This is because x86_64 can have some 16-byte entries as well as 8-byte ones. Signed-off-by: NGlauber de Oliveira Costa <gcosta@redhat.com> CC: Zachary Amsden <zach@vmware.com> CC: Jeremy Fitzhardinge <Jeremy.Fitzhardinge.citrix.com> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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this patch changes write_idt_entry signature. It now takes a gate_desc instead of the a and b parameters. It will allow it to be later unified between i386 and x86_64. Signed-off-by: NGlauber de Oliveira Costa <gcosta@redhat.com> CC: Zachary Amsden <zach@vmware.com> CC: Jeremy Fitzhardinge <Jeremy.Fitzhardinge.citrix.com> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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This patch unifies struct desc_ptr between i386 and x86_64. They can be expressed in the exact same way in C code, only having to change the name of one of them. As Xgt_desc_struct is ugly and big, this is the one that goes away. There's also a padding field in i386, but it is not really needed in the C structure definition. Signed-off-by: NGlauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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This patche changes the native_write_msr() and friends interface to explicitly take 2 32-bit registers instead of a 64-bit value. The change will ease the merge with 64-bit code. As the 64-bit value will be passed as two registers anyway in i386, the PVOP_CALL interface has to account for that and use low/high parameters It would force the x86_64 version to be different. The change does not make i386 generated code less efficient. As said above, it would get the values from two registers anyway. Signed-off-by: NGlauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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the rdpmc instruction gets a counter argument in rcx. However, the i386 version was ignoring it. To make both x86_64 and i386 versions the same, as well as to comply with the instruction semantics, this parameter is added in the i386 version Signed-off-by: NGlauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 H. Peter Anvin 提交于
This changes size-specific register names (eip/rip, esp/rsp, etc.) to generic names in the thread and tss structures. Signed-off-by: NH. Peter Anvin <hpa@zytor.com> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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This patch consolidates the irqflags include files containing common paravirt definitions. The native definition for interrupt handling, halt, and such, are the same for 32 and 64 bit, and they are kept in irqflags.h. the differences are split in the arch-specific files. The syscall function, irq_enable_sysexit, has a very specific i386 naming, and its name is then changed to a more general one. Signed-off-by: NGlauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org> Acked-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Thomas Gleixner 提交于
Use u32 so 32 and 64bit have the same interface. Andrew Morton: xen, lguest build fixes Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 17 10月, 2007 2 次提交
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由 Jeremy Fitzhardinge 提交于
Currently, the set_lazy_mode pv_op is overloaded with 5 functions: 1. enter lazy cpu mode 2. leave lazy cpu mode 3. enter lazy mmu mode 4. leave lazy mmu mode 5. flush pending batched operations This complicates each paravirt backend, since it needs to deal with all the possible state transitions, handling flushing, etc. In particular, flushing is quite distinct from the other 4 functions, and seems to just cause complication. This patch removes the set_lazy_mode operation, and adds "enter" and "leave" lazy mode operations on mmu_ops and cpu_ops. All the logic associated with enter and leaving lazy states is now in common code (basically BUG_ONs to make sure that no mode is current when entering a lazy mode, and make sure that the mode is current when leaving). Also, flush is handled in a common way, by simply leaving and re-entering the lazy mode. The result is that the Xen, lguest and VMI lazy mode implementations are much simpler. Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Cc: Andi Kleen <ak@suse.de> Cc: Zach Amsden <zach@vmware.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Avi Kivity <avi@qumranet.com> Cc: Anthony Liguory <aliguori@us.ibm.com> Cc: "Glauber de Oliveira Costa" <glommer@gmail.com> Cc: Jun Nakajima <jun.nakajima@intel.com>
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由 Jeremy Fitzhardinge 提交于
This patch refactors the paravirt_ops structure into groups of functionally related ops: pv_info - random info, rather than function entrypoints pv_init_ops - functions used at boot time (some for module_init too) pv_misc_ops - lazy mode, which didn't fit well anywhere else pv_time_ops - time-related functions pv_cpu_ops - various privileged instruction ops pv_irq_ops - operations for managing interrupt state pv_apic_ops - APIC operations pv_mmu_ops - operations for managing pagetables There are several motivations for this: 1. Some of these ops will be general to all x86, and some will be i386/x86-64 specific. This makes it easier to share common stuff while allowing separate implementations where needed. 2. At the moment we must export all of paravirt_ops, but modules only need selected parts of it. This allows us to export on a case by case basis (and also choose which export license we want to apply). 3. Functional groupings make things a bit more readable. Struct paravirt_ops is now only used as a template to generate patch-site identifiers, and to extract function pointers for inserting into jmp/calls when patching. It is only instantiated when needed. Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au> Cc: Andi Kleen <ak@suse.de> Cc: Zach Amsden <zach@vmware.com> Cc: Avi Kivity <avi@qumranet.com> Cc: Anthony Liguory <aliguori@us.ibm.com> Cc: "Glauber de Oliveira Costa" <glommer@gmail.com> Cc: Jun Nakajima <jun.nakajima@intel.com>
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- 11 10月, 2007 1 次提交
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由 Thomas Gleixner 提交于
Move the headers to include/asm-x86 and fixup the header install make rules Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 12 8月, 2007 1 次提交
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由 Andi Kleen 提交于
Commit 19d36ccd "x86: Fix alternatives and kprobes to remap write-protected kernel text" uses code which is being patched for patching. In particular, paravirt_ops does patching in two stages: first it calls paravirt_ops.patch, then it fills any remaining instructions with nop_out(). nop_out calls text_poke() which calls lookup_address() which calls pgd_val() (aka paravirt_ops.pgd_val): that call site is one of the places we patch. If we always do patching as one single call to text_poke(), we only need make sure we're not patching the memcpy in text_poke itself. This means the prototype to paravirt_ops.patch needs to change, to marshal the new code into a buffer rather than patching in place as it does now. It also means all patching goes through text_poke(), which is known to be safe (apply_alternatives is also changed to make a single patch). AK: fix compilation on x86-64 (bad rusty!) AK: fix boot on x86-64 (sigh) AK: merged with other patches Signed-off-by: NRusty Russell <rusty@rustcorp.com.au> Signed-off-by: NAndi Kleen <ak@suse.de> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 18 7月, 2007 4 次提交
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由 Jeremy Fitzhardinge 提交于
The tsc-based get_scheduled_cycles interface is not a good match for Xen's runstate accounting, which reports everything in nanoseconds. This patch replaces this interface with a sched_clock interface, which matches both Xen and VMI's requirements. In order to do this, we: 1. replace get_scheduled_cycles with sched_clock 2. hoist cycles_2_ns into a common header 3. update vmi accordingly One thing to note: because sched_clock is implemented as a weak function in kernel/sched.c, we must define a real function in order to override this weak binding. This means the usual paravirt_ops technique of using an inline function won't work in this case. Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Cc: Zachary Amsden <zach@vmware.com> Cc: Dan Hecht <dhecht@vmware.com> Cc: john stultz <johnstul@us.ibm.com>
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由 Jeremy Fitzhardinge 提交于
In a virtual environment, device drivers such as legacy IDE will waste quite a lot of time probing for their devices which will never appear. This helper function allows a paravirt implementation to lay claim to the whole iomem and ioport space, thereby disabling all device drivers trying to claim IO resources. Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NChris Wright <chrisw@sous-sol.org> Cc: Rusty Russell <rusty@rustcorp.com.au>
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由 Jeremy Fitzhardinge 提交于
Add a hook so that the paravirt backend knows when the allocator is ready. This is useful for the obvious reason that the allocator is available, but the other side-effect of having the bootmem allocator available is that each page now has an associated "struct page". Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com>
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由 Jeremy Fitzhardinge 提交于
It's useful to know which mm is allocating a pagetable. Xen uses this to determine whether the pagetable being added to is pinned or not. Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com>
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- 26 6月, 2007 1 次提交
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由 Björn Steinbrink 提交于
wrmsrl() is broken, dropping the upper 32bits of the value to be written. This broke the NMI watchdog on AMD hardware. (and it probably broke other code too.) Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 11 5月, 2007 1 次提交
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由 Eric W. Biederman 提交于
This reverts commit c9ccf30d. Entering the kernel at startup_32 without passing our real mode data in %esi, and without guaranteeing that physical and virtual addresses are identity mapped makes head.S impossible to maintain. The only user of this infrastructure is lguest which is not merged so nothing we currently support will break by removing this over designed nightmare, and only the pending lguest patches will be affected. The pending Xen patches have a different entry point that they use. We are currently discussing what Xen and lguest need to do to boot the kernel in a more normal fashion so using startup_32 in this weird manner is clearly not their long term direction. So let's remove this code in head.S before it causes brain damage to people trying to maintain head.S Cc: Chris Wright <chrisw@sous-sol.org> Cc: Andi Kleen <ak@suse.de> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Zachary Amsden <zach@vmware.com> CC: H. Peter Anvin <hpa@zytor.com> Signed-off-by: NEric W. Biederman <ebiederm@xmission.com> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 10 5月, 2007 1 次提交
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由 H. Peter Anvin 提交于
All users to the two-part rdtsc() macro have already switched to using rdtscl() or rdtscll(). Remove the now-obsolete macro. Signed-off-by: NH. Peter Anvin <hpa@zytor.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 03 5月, 2007 14 次提交
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由 Jeremy Fitzhardinge 提交于
In shadow mode hypervisors, ptep_get_and_clear achieves the desired purpose of keeping the shadows in sync by issuing a native_get_and_clear, followed by a call to pte_update, which indicates the PTE has been modified. Direct mode hypervisors (Xen) have no need for this anyway, and will trap the update using writable pagetables. This means no hypervisor makes use of ptep_get_and_clear; there is no reason to have it in the paravirt-ops structure. Change confusing terminology about raw vs. native functions into consistent use of native_pte_xxx for operations which do not invoke paravirt-ops. Signed-off-by: NZachary Amsden <zach@vmware.com> Signed-off-by: NAndi Kleen <ak@suse.de>
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由 Jeremy Fitzhardinge 提交于
Replace all the open-coded macros for generating calls with a pair of more general macros (__PVOP_CALL/VCALL), and redefine all the PVOP_V?CALL[0-4] in terms of them. [ Andrew, Andi: this should slot in immediately after "Document asm-i386/paravirt.h" (paravirt_ops-document-asm-i386-paravirth.patch) ] Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NAndi Kleen <ak@suse.de> Cc: Ingo Molnar <mingo@elte.hu>
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由 Jeremy Fitzhardinge 提交于
Remove #defines, add enum for PARAVIRT_LAZY_FLUSH. Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NAndi Kleen <ak@suse.de>
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由 Jeremy Fitzhardinge 提交于
Xen and VMI both have special requirements when mapping a highmem pte page into the kernel address space. These can be dealt with by adding a new kmap_atomic_pte() function for mapping highptes, and hooking it into the paravirt_ops infrastructure. Xen specifically wants to map the pte page RO, so this patch exposes a helper function, kmap_atomic_prot, which maps the page with the specified page protections. This also adds a kmap_flush_unused() function to clear out the cached kmap mappings. Xen needs this to clear out any potential stray RW mappings of pages which will become part of a pagetable. [ Zach - vmi.c will need some attention after this patch. It wasn't immediately obvious to me what needs to be done. ] Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NAndi Kleen <ak@suse.de> Cc: Zachary Amsden <zach@vmware.com>
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由 Jeremy Fitzhardinge 提交于
Back out the map_pt_hook to clear the way for kmap_atomic_pte. Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NAndi Kleen <ak@suse.de> Cc: Zachary Amsden <zach@vmware.com>
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由 Jeremy Fitzhardinge 提交于
This patch adds a pv_op for flush_tlb_others. Linux running on native hardware uses cross-CPU IPIs to flush the TLB on any CPU which may have a particular mm's pagetable entries cached in its TLB. This is inefficient in a paravirtualized environment, since the hypervisor knows which real CPUs actually contain cached mappings, which may be a small subset of a guest's VCPUs. Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NAndi Kleen <ak@suse.de>
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由 Jeremy Fitzhardinge 提交于
Implement the actual patching machinery. paravirt_patch_default() contains the logic to automatically patch a callsite based on a few simple rules: - if the paravirt_op function is paravirt_nop, then patch nops - if the paravirt_op function is a jmp target, then jmp to it - if the paravirt_op function is callable and doesn't clobber too much for the callsite, call it directly paravirt_patch_default is suitable as a default implementation of paravirt_ops.patch, will remove most of the expensive indirect calls in favour of either a direct call or a pile of nops. Backends may implement their own patcher, however. There are several helper functions to help with this: paravirt_patch_nop nop out a callsite paravirt_patch_ignore leave the callsite as-is paravirt_patch_call patch a call if the caller and callee have compatible clobbers paravirt_patch_jmp patch in a jmp paravirt_patch_insns patch some literal instructions over the callsite, if they fit This patch also implements more direct patches for the native case, so that when running on native hardware many common operations are implemented inline. Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NAndi Kleen <ak@suse.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Zachary Amsden <zach@vmware.com> Cc: Anthony Liguori <anthony@codemonkey.ws> Acked-by: NIngo Molnar <mingo@elte.hu>
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由 Jeremy Fitzhardinge 提交于
Clean things up, and broadly document: - the paravirt_ops functions themselves - the patching mechanism Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NAndi Kleen <ak@suse.de> Cc: Rusty Russell <rusty@rustcorp.com.au>
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由 Jeremy Fitzhardinge 提交于
Wrap a set of interesting paravirt_ops calls in a wrapper which makes the callsites available for patching. Unfortunately this is pretty ugly because there's no way to get gcc to generate a function call, but also wrap just the callsite itself with the necessary labels. This patch supports functions with 0-4 arguments, and either void or returning a value. 64-bit arguments must be split into a pair of 32-bit arguments (lower word first). Small structures are returned in registers. Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NAndi Kleen <ak@suse.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Zachary Amsden <zach@vmware.com> Cc: Anthony Liguori <anthony@codemonkey.ws>
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由 Jeremy Fitzhardinge 提交于
Fix a few clobbers to include the return register. The clobbers set is the set of all registers modified (or may be modified) by the code snippet, regardless of whether it was deliberate or accidental. Also, make sure that callsites which are used in contexts which don't allow clobbers actually save and restore all clobberable registers. Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NAndi Kleen <ak@suse.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Zachary Amsden <zach@vmware.com>
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由 Jeremy Fitzhardinge 提交于
Use patch type identifiers derived from the offset of the operation in the paravirt_ops structure. This avoids having to maintain a separate enum for patch site types. Also, since the identifier is derived from the offset into paravirt_ops, the offset can be derived from the identifier. This is used to remove replicated information in the various callsite macros, which has been a source of bugs in the past. This patch also drops the fused save_fl+cli operation, which doesn't really add much and makes things more complex - specifically because it breaks the 1:1 relationship between identifiers and offsets. If this operation turns out to be particularly beneficial, then the right answer is to define a new entrypoint for it. Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NAndi Kleen <ak@suse.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Zachary Amsden <zach@vmware.com>
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由 Jeremy Fitzhardinge 提交于
Rename struct paravirt_patch to paravirt_patch_site, so that it clearly refers to a callsite, and not the patch which may be applied to that callsite. Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NAndi Kleen <ak@suse.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Zachary Amsden <zach@vmware.com>
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由 Jeremy Fitzhardinge 提交于
Add hooks to allow a paravirt implementation to track the lifetime of an mm. Paravirtualization requires three hooks, but only two are needed in common code. They are: arch_dup_mmap, which is called when a new mmap is created at fork arch_exit_mmap, which is called when the last process reference to an mm is dropped, which typically happens on exit and exec. The third hook is activate_mm, which is called from the arch-specific activate_mm() macro/function, and so doesn't need stub versions for other architectures. It's called when an mm is first used. Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NAndi Kleen <ak@suse.de> Cc: linux-arch@vger.kernel.org Cc: James Bottomley <James.Bottomley@SteelEye.com> Acked-by: NIngo Molnar <mingo@elte.hu>
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由 Jeremy Fitzhardinge 提交于
Normally when running in PAE mode, the 4th PMD maps the kernel address space, which can be shared among all processes (since they all need the same kernel mappings). Xen, however, does not allow guests to have the kernel pmd shared between page tables, so parameterize pgtable.c to allow both modes of operation. There are several side-effects of this. One is that vmalloc will update the kernel address space mappings, and those updates need to be propagated into all processes if the kernel mappings are not intrinsically shared. In the non-PAE case, this is done by maintaining a pgd_list of all processes; this list is used when all process pagetables must be updated. pgd_list is threaded via otherwise unused entries in the page structure for the pgd, which means that the pgd must be page-sized for this to work. Normally the PAE pgd is only 4x64 byte entries large, but Xen requires the PAE pgd to page aligned anyway, so this patch forces the pgd to be page aligned+sized when the kernel pmd is unshared, to accomodate both these requirements. Also, since there may be several distinct kernel pmds (if the user/kernel split is below 3G), there's no point in allocating them from a slab cache; they're just allocated with get_free_page and initialized appropriately. (Of course the could be cached if there is just a single kernel pmd - which is the default with a 3G user/kernel split - but it doesn't seem worthwhile to add yet another case into this code). [ Many thanks to wli for review comments. ] Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: NWilliam Lee Irwin III <wli@holomorphy.com> Signed-off-by: NAndi Kleen <ak@suse.de> Cc: Zachary Amsden <zach@vmware.com> Cc: Christoph Lameter <clameter@sgi.com> Acked-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
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