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path: root/include/asm-i386/paravirt.h
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2007-06-25fix nmi_watchdog=2 bootup hangBjörn Steinbrink
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: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-10Revert "[PATCH] paravirt: Add startup infrastructure for paravirtualization"Eric W. Biederman
This reverts commit c9ccf30d77f04064fe5436027ab9d2230c7cdd94. 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: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09i386: remove unused rdtsc() macroH. Peter Anvin
All users to the two-part rdtsc() macro have already switched to using rdtscl() or rdtscll(). Remove the now-obsolete macro. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-02[PATCH] i386: PARAVIRT: drop unused ptep_get_and_clearJeremy Fitzhardinge
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: Zachary Amsden <zach@vmware.com> Signed-off-by: Andi Kleen <ak@suse.de>
2007-05-02[PATCH] i386: PARAVIRT: Clean up paravirt patchable wrappersJeremy Fitzhardinge
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: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-02[PATCH] i386: PARAVIRT: Use enums for paravirt lazy flush modiJeremy Fitzhardinge
Remove #defines, add enum for PARAVIRT_LAZY_FLUSH. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de>
2007-05-02[PATCH] i386: PARAVIRT: add kmap_atomic_pte for mapping highpte pagesJeremy Fitzhardinge
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: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Zachary Amsden <zach@vmware.com>
2007-05-02[PATCH] i386: PARAVIRT: revert map_pt_hook.Jeremy Fitzhardinge
Back out the map_pt_hook to clear the way for kmap_atomic_pte. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Zachary Amsden <zach@vmware.com>
2007-05-02[PATCH] i386: PARAVIRT: add flush_tlb_others paravirt_opJeremy Fitzhardinge
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: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de>
2007-05-02[PATCH] i386: PARAVIRT: add common patching machineryJeremy Fitzhardinge
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: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi 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: Ingo Molnar <mingo@elte.hu>
2007-05-02[PATCH] i386: PARAVIRT: Document asm-i386/paravirt.hJeremy Fitzhardinge
Clean things up, and broadly document: - the paravirt_ops functions themselves - the patching mechanism Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Rusty Russell <rusty@rustcorp.com.au>
2007-05-02[PATCH] i386: PARAVIRT: Consistently wrap paravirt ops callsites to make ↵Jeremy Fitzhardinge
them patchable 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: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Zachary Amsden <zach@vmware.com> Cc: Anthony Liguori <anthony@codemonkey.ws>
2007-05-02[PATCH] i386: PARAVIRT: Fix patch site clobbers to include return registerJeremy Fitzhardinge
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: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Zachary Amsden <zach@vmware.com>
2007-05-02[PATCH] i386: PARAVIRT: Use patch site IDs computed from offset in ↵Jeremy Fitzhardinge
paravirt_ops structure 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: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Zachary Amsden <zach@vmware.com>
2007-05-02[PATCH] i386: PARAVIRT: rename struct paravirt_patch to paravirt_patch_site ↵Jeremy Fitzhardinge
for clarity 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: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Zachary Amsden <zach@vmware.com>
2007-05-02[PATCH] x86: PARAVIRT: add hooks to intercept mm creation and destructionJeremy Fitzhardinge
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: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: linux-arch@vger.kernel.org Cc: James Bottomley <James.Bottomley@SteelEye.com> Acked-by: Ingo Molnar <mingo@elte.hu>
2007-05-02[PATCH] i386: PARAVIRT: Allow paravirt backend to choose kernel PMD sharingJeremy Fitzhardinge
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: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: William Lee Irwin III <wli@holomorphy.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Zachary Amsden <zach@vmware.com> Cc: Christoph Lameter <clameter@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2007-05-02[PATCH] i386: PARAVIRT: Hooks to set up initial pagetableJeremy Fitzhardinge
This patch introduces paravirt_ops hooks to control how the kernel's initial pagetable is set up. In the case of a native boot, the very early bootstrap code creates a simple non-PAE pagetable to map the kernel and physical memory. When the VM subsystem is initialized, it creates a proper pagetable which respects the PAE mode, large pages, etc. When booting under a hypervisor, there are many possibilities for what paging environment the hypervisor establishes for the guest kernel, so the constructon of the kernel's pagetable depends on the hypervisor. In the case of Xen, the hypervisor boots the kernel with a fully constructed pagetable, which is already using PAE if necessary. Also, Xen requires particular care when constructing pagetables to make sure all pagetables are always mapped read-only. In order to make this easier, kernel's initial pagetable construction has been changed to only allocate and initialize a pagetable page if there's no page already present in the pagetable. This allows the Xen paravirt backend to make a copy of the hypervisor-provided pagetable, allowing the kernel to establish any more mappings it needs while keeping the existing ones. A slightly subtle point which is worth highlighting here is that Xen requires all kernel mappings to share the same pte_t pages between all pagetables, so that updating a kernel page's mapping in one pagetable is reflected in all other pagetables. This makes it possible to allocate a page and attach it to a pagetable without having to explicitly enumerate that page's mapping in all pagetables. And: +From: "Eric W. Biederman" <ebiederm@xmission.com> If we don't set the leaf page table entries it is quite possible that will inherit and incorrect page table entry from the initial boot page table setup in head.S. So we need to redo the effort here, so we pick up PSE, PGE and the like. Hypervisors like Xen require that their page tables be read-only, which is slightly incompatible with our low identity mappings, however I discussed this with Jeremy he has modified the Xen early set_pte function to avoid problems in this area. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-02[PATCH] i386: PARAVIRT: Add pagetable accessors to pack and unpack pagetable ↵Jeremy Fitzhardinge
entries Add a set of accessors to pack, unpack and modify page table entries (at all levels). This allows a paravirt implementation to control the contents of pgd/pmd/pte entries. For example, Xen uses this to convert the (pseudo-)physical address into a machine address when populating a pagetable entry, and converting back to pphys address when an entry is read. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: Ingo Molnar <mingo@elte.hu>
2007-05-02[PATCH] i386: PARAVIRT: use paravirt_nop to consistently mark no-op operationsJeremy Fitzhardinge
Add a _paravirt_nop function for use as a stub for no-op operations, and paravirt_nop #defined void * version to make using it easier (since all its uses are as a void *). This is useful to allow the patcher to automatically identify noop operations so it can simply nop out the callsite. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: Ingo Molnar <mingo@elte.hu> [mingo] but only as a cleanup of the current open-coded (void *) casts. My problem with this is that it loses the types. Not that there is much to check for, but still, this adds some assumptions about how function calls look like
2007-05-02[PATCH] i386: rationalize paravirt wrappersRusty Russell
paravirt.c used to implement native versions of all low-level functions. Far cleaner is to have the native versions exposed in the headers and as inline native_XXX, and if !CONFIG_PARAVIRT, then simply #define XXX native_XXX. There are several nice side effects: 1) write_dt_entry() now takes the correct "struct Xgt_desc_struct *" not "void *". 2) load_TLS is reintroduced to the for loop, not manually unrolled with a #error in case the bounds ever change. 3) Macros become inlines, with type checking. 4) Access to the native versions is trivial for KVM, lguest, Xen and others who might want it. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <ak@muc.de> Cc: Avi Kivity <avi@qumranet.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2007-04-08[PATCH] Proper fix for highmem kmap_atomic functions for VMI for 2.6.21Zachary Amsden
Since lazy MMU batching mode still allows interrupts to enter, it is possible for interrupt handlers to try to use kmap_atomic, which fails when lazy mode is active, since the PTE update to highmem will be delayed. The best workaround is to issue an explicit flush in kmap_atomic_functions case; this is the only way nested PTE updates can happen in the interrupt handler. Thanks to Jeremy Fitzhardinge for noting the bug and suggestions on a fix. This patch gets reverted again when we start 2.6.22 and the bug gets fixed differently. Signed-off-by: Zachary Amsden <zach@vmware.com> Cc: Andi Kleen <ak@muc.de> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-14[PATCH] fastcall still doesn't make sense in paravirtAl Viro
Andi had removed a bunch of those, but one more had creeped in... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-05[PATCH] vmi: pit overrideZachary Amsden
The time_init_hook in paravirt-ops no longer functions in the correct manner after the integration of the hrtimers code. The problem is that now the call path for time initialization is: time_init : late_time_init = hpet_time_init; late_time_init -> hpet_time_init: setup_pit_timer (BAD) do_time_init --> (via paravirt.h) time_init_hook --> (via arch_hooks.h) time_init_hook (in SUBARCH/setup.c) If this isn't confusing enough, the paravirt case goes through an indirect function pointer in the paravirt-ops table. The problem is, by the time the paravirt hook is called, the pit timer is already enabled. But paravirt guests have their own timer, and don't want to use the PIT. Rather than intensify the struggle for power going on here, just make it all nice and simple and just unconditionally do all timer setup in the late_time_init hook. This also has the advantage of enabling timers in the same place in all code paths, so everyone has the same bugs and we don't have outliers who break other code because they turn on timer too early or too late. So the paravirt-ops time init function is now by default hpet_time_init, which is the time init function used for native hardware. Paravirt guests have the chance to override this when they setup the paravirt-ops table, and should need no change. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-05[PATCH] vmi: paravirt drop udelay opZachary Amsden
Not respecting udelay causes problems with any virtual hardware that is passed through to real hardware. This can be noticed by any device that interacts with the real world in real time - like AP startup, which takes real time. Or keyboard LEDs, which should blink in real-time. Or floppy drives, but only when passed through to a real floppy controller on OSes which can't sufficiently buffer the floppy commands to emulate a zero latency floppy. Or IDE drives, when connecting to a physical CDROM. This was mostly a hack to get the kernel to boot faster, but it introduced a number of misvirtualization bugs, and Alan and Pavel argued pretty strongly against it. We were the only client, and now want to clean up this cruft. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-05[PATCH] vmi: fix highpteZachary Amsden
Provide a PT map hook for HIGHPTE kernels to designate where they are mapping page tables. This information is required so the physical address of PTE updates can be determined; otherwise, the mm layer would have to carry the physical address all the way to each PTE modification callsite, which is even more hideous that the macros required to provide the proper hooks. So lets not mess up arch neutral code to achieve this, but keep the horror in an #ifdef HIGHPTE in include/asm-i386/pgtable.h. I had to use macros here because some types are not yet defined in all the include paths for this header. This patch is absolutely required for HIGHPTE kernels to operate properly with VMI. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-05[PATCH] vmi: cpu cycles fixZachary Amsden
In order to share the common code in tsc.c which does CPU Khz calibration, we need to make an accurate value of CPU speed available to the tsc.c code. This value loses a lot of precision in a VM because of the timing differences with real hardware, but we need it to be as precise as possible so the guest can make accurate time calculations with the cycle counters. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-05[PATCH] vmi: sched clock paravirt op fixZachary Amsden
The custom_sched_clock hook is broken. The result from sched_clock needs to be in nanoseconds, not in CPU cycles. The TSC is insufficient for this purpose, because TSC is poorly defined in a virtual environment, and mostly represents real world time instead of scheduled process time (which can be interrupted without notice when a virtual machine is descheduled). To make the scheduler consistent, we must expose a different nature of time, that is scheduled time. So deprecate this custom_sched_clock hack and turn it into a paravirt-op, as it should have been all along. This allows the tsc.c code which converts cycles to nanoseconds to be shared by all paravirt-ops backends. It is unfortunate to add a new paravirt-op, but this is a very distinct abstraction which is clearly different for all virtual machine implementations, and it gets rid of an ugly indirect function which I ashamedly admit I hacked in to try to get this to work earlier, and then even got in the wrong units. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-13[PATCH] i386: Remove fastcall in paravirt.[ch]Andi Kleen
Not needed because fastcall is always default now Signed-off-by: Andi Kleen <ak@suse.de>
2007-02-13[PATCH] i386: vMI timer patchesZachary Amsden
VMI timer code. It works by taking over the local APIC clock when APIC is configured, which requires a couple hooks into the APIC code. The backend timer code could be commonized into the timer infrastructure, but there are some pieces missing (stolen time, in particular), and the exact semantics of when to do accounting for NO_IDLE need to be shared between different hypervisors as well. So for now, VMI timer is a separate module. [Adrian Bunk: cleanups] Subject: VMI timer patches Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <ak@suse.de> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andrew Morton <akpm@osdl.org>
2007-02-13[PATCH] i386: SMP boot hook for paravirtZachary Amsden
Add VMI SMP boot hook. We emulate a regular boot sequence and use the same APIC IPI initiation, we just poke magic values to load into the CPU state when the startup IPI is received, rather than having to jump through a real mode trampoline. This is all that was needed to get SMP to work. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <ak@suse.de> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andrew Morton <akpm@osdl.org>
2007-02-13[PATCH] i386: paravirt CPU hypercall batching modeZachary Amsden
The VMI ROM has a mode where hypercalls can be queued and batched. This turns out to be a significant win during context switch, but must be done at a specific point before side effects to CPU state are visible to subsequent instructions. This is similar to the MMU batching hooks already provided. The same hooks could be used by the Xen backend to implement a context switch multicall. To explain a bit more about lazy modes in the paravirt patches, basically, the idea is that only one of lazy CPU or MMU mode can be active at any given time. Lazy MMU mode is similar to this lazy CPU mode, and allows for batching of multiple PTE updates (say, inside a remap loop), but to avoid keeping some kind of state machine about when to flush cpu or mmu updates, we just allow one or the other to be active. Although there is no real reason a more comprehensive scheme could not be implemented, there is also no demonstrated need for this extra complexity. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <ak@suse.de> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andrew Morton <akpm@osdl.org>
2007-02-13[PATCH] MM: page allocation hooks for VMI backendZachary Amsden
The VMI backend uses explicit page type notification to track shadow page tables. The allocation of page table roots is especially tricky. We need to clone the root for non-PAE mode while it is protected under the pgd lock to correctly copy the shadow. We don't need to allocate pgds in PAE mode, (PDPs in Intel terminology) as they only have 4 entries, and are cached entirely by the processor, which makes shadowing them rather simple. For base page table level allocation, pmd_populate provides the exact hook point we need. Also, we need to allocate pages when splitting a large page, and we must release pages before returning the page to any free pool. Despite being required with these slightly odd semantics for VMI, Xen also uses these hooks to determine the exact moment when page tables are created or released. AK: All nops for other architectures Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <ak@suse.de> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-07[PATCH] paravirt: Add MMU virtualization to paravirt_opsRusty Russell
Add the three bare TLB accessor functions to paravirt-ops. Most amusingly, flush_tlb is redefined on SMP, so I can't call the paravirt op flush_tlb. Instead, I chose to indicate the actual flush type, kernel (global) vs. user (non-global). Global in this sense means using the global bit in the page table entry, which makes TLB entries persistent across CR3 reloads, not global as in the SMP sense of invoking remote shootdowns, so the term is confusingly overloaded. AK: folded in fix from Zach for PAE compilation Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-07[PATCH] paravirt: Add APIC accessors to paravirt-ops.Rusty Russell
Add APIC accessors to paravirt-ops. Unfortunately, we need two write functions, as some older broken hardware requires workarounds for Pentium APIC errata - this is the purpose of apic_write_atomic. AK: replaced __inline with inline Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-07[PATCH] paravirt: Add startup infrastructure for paravirtualizationRusty Russell
1) Each hypervisor writes a probe function to detect whether we are running under that hypervisor. paravirt_probe() registers this function. 2) If vmlinux is booted with ring != 0, we call all the probe functions (with registers except %esp intact) in link order: the winner will not return. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Zachary Amsden <zach@vmware.com> Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-07[PATCH] paravirt: Patch inline replacements for paravirt interceptsRusty Russell
It turns out that the most called ops, by several orders of magnitude, are the interrupt manipulation ops. These are obvious candidates for patching, so mark them up and create infrastructure for it. The method used is that the ops structure has a patch function, which is called for each place which needs to be patched: this returns a number of instructions (the rest are NOP-padded). Usually we can spare a register (%eax) for the binary patched code to use, but in a couple of critical places in entry.S we can't: we make the clobbers explicit at the call site, and manually clobber the allowed registers in debug mode as an extra check. And: Don't abuse CONFIG_DEBUG_KERNEL, add CONFIG_DEBUG_PARAVIRT. And: AK: Fix warnings in x86-64 alternative.c build And: AK: Fix compilation with defconfig And: ^From: Andrew Morton <akpm@osdl.org> Some binutlises still like to emit references to __stop_parainstructions and __start_parainstructions. And: AK: Fix warnings about unused variables when PARAVIRT is disabled. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-07[PATCH] paravirt: header and stubs for paravirtualisationRusty Russell
Create a paravirt.h header for all the critical operations which need to be replaced with hypervisor calls, and include that instead of defining native operations, when CONFIG_PARAVIRT. This patch does the dumbest possible replacement of paravirtualized instructions: calls through a "paravirt_ops" structure. Currently these are function implementations of native hardware: hypervisors will override the ops structure with their own variants. All the pv-ops functions are declared "fastcall" so that a specific register-based ABI is used, to make inlining assember easier. And: +From: Andy Whitcroft <apw@shadowen.org> The paravirt ops introduce a 'weak' attribute onto memory_setup(). Code ordering leads to the following warnings on x86: arch/i386/kernel/setup.c:651: warning: weak declaration of `memory_setup' after first use results in unspecified behavior Move memory_setup() to avoid this. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Zachary Amsden <zach@vmware.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Andy Whitcroft <apw@shadowen.org>