- Feb 10, 2019
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Juergen Gross authored
set_pmd_at() calls native_set_pmd() unconditionally on x86. This was fine as long as only huge page entries were written via set_pmd_at(), as Xen pv guests don't support those. Commit 2c91bd4a ("mm: speed up mremap by 20x on large regions") introduced a usage of set_pmd_at() possible on pv guests, leading to failures like: BUG: unable to handle kernel paging request at ffff888023e26778 #PF error: [PROT] [WRITE] RIP: e030:move_page_tables+0x7c1/0xae0 move_vma.isra.3+0xd1/0x2d0 __se_sys_mremap+0x3c6/0x5b0 do_syscall_64+0x49/0x100 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Make set_pmd_at() paravirt aware by just letting it use set_pmd(). Fixes: 2c91bd4a ("mm: speed up mremap by 20x on large regions") Reported-by:
Sander Eikelenboom <linux@eikelenboom.it> Signed-off-by:
Juergen Gross <jgross@suse.com> Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> Cc: xen-devel@lists.xenproject.org Cc: boris.ostrovsky@oracle.com Cc: sstabellini@kernel.org Cc: hpa@zytor.com Cc: bp@alien8.de Cc: torvalds@linux-foundation.org Link: https://lkml.kernel.org/r/20190210074056.11842-1-jgross@suse.com
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- Feb 02, 2019
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Johannes Weiner authored
"Resource Control" is a very broad term for this CPU feature, and a term that is also associated with containers, cgroups etc. This can easily cause confusion. Make the user prompt more specific. Match the config symbol name. [ bp: In the future, the corresponding ARM arch-specific code will be under ARM_CPU_RESCTRL and the arch-agnostic bits will be carved out under the CPU_RESCTRL umbrella symbol. ] Signed-off-by:
Johannes Weiner <hannes@cmpxchg.org> Signed-off-by:
Borislav Petkov <bp@suse.de> Cc: Babu Moger <Babu.Moger@amd.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morse <james.morse@arm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: linux-doc@vger.kernel.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Pu Wen <puwen@hygon.cn> Cc: Reinette Chatre <reinette.chatre@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190130195621.GA30653@cmpxchg.org
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- Jan 29, 2019
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Kan Liang authored
Add the Atom Tremont model number to the Intel family list. [ Tony: Also update comment at head of file to say "_X" suffix is also used for microserver parts. ] Signed-off-by:
Kan Liang <kan.liang@linux.intel.com> Signed-off-by:
Qiuxu Zhuo <qiuxu.zhuo@intel.com> Signed-off-by:
Tony Luck <tony.luck@intel.com> Signed-off-by:
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- Jan 15, 2019
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Dave Hansen authored
Memory protection key behavior should be the same in a child as it was in the parent before a fork. But, there is a bug that resets the state in the child at fork instead of preserving it. The creation of new mm's is a bit convoluted. At fork(), the code does: 1. memcpy() the parent mm to initialize child 2. mm_init() to initalize some select stuff stuff 3. dup_mmap() to create true copies that memcpy() did not do right For pkeys two bits of state need to be preserved across a fork: 'execute_only_pkey' and 'pkey_allocation_map'. Those are preserved by the memcpy(), but mm_init() invokes init_new_context() which overwrites 'execute_only_pkey' and 'pkey_allocation_map' with "new" values. The author of the code erroneously believed that init_new_context is *only* called at execve()-time. But, alas, init_new_context() is used at execve() and fork(). The result is that, after a fork(), the child's pkey state ends up looking like it does after an execve(), which is totally wrong. pkeys that are already allocated can be allocated again, for instance. To fix this, add code called by dup_mmap() to copy the pkey state from parent to child explicitly. Also add a comment above init_new_context() to make it more clear to the next poor sod what this code is used for. Fixes: e8c24d3a ("x86/pkeys: Allocation/free syscalls") Signed-off-by:
Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by:
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- Jan 09, 2019
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Borislav Petkov authored
CONFIG_RESCTRL is too generic. The final goal is to have a generic option called like this which is selected by the arch-specific ones CONFIG_X86_RESCTRL and CONFIG_ARM64_RESCTRL. The generic one will cover the resctrl filesystem and other generic and shared bits of functionality. Signed-off-by:
Ingo Molnar <mingo@kernel.org> Requested-by:
Linus Torvalds <torvalds@linux-foundation.org> Cc: Babu Moger <babu.moger@amd.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: James Morse <james.morse@arm.com> Cc: Reinette Chatre <reinette.chatre@intel.com> Cc: Tony Luck <tony.luck@intel.com> Cc: x86@kernel.org Link: http://lkml.kernel.org/r/20190108171401.GC12235@zn.tnic
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- Jan 06, 2019
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Masahiro Yamada authored
Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label". The jump label is controlled by HAVE_JUMP_LABEL, which is defined like this: #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) # define HAVE_JUMP_LABEL #endif We can improve this by testing 'asm goto' support in Kconfig, then make JUMP_LABEL depend on CC_HAS_ASM_GOTO. Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will match to the real kernel capability. Signed-off-by:
Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Tested-by:
Sedat Dilek <sedat.dilek@gmail.com>
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- Jan 05, 2019
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Linus Torvalds authored
This has been broken forever, and nobody ever really noticed because it's purely a performance issue. Long long ago, in commit 6175ddf0 ("x86: Clean up mem*io functions") Brian Gerst simplified the memory copies to and from iomem, since on x86, the instructions to access iomem are exactly the same as the regular instructions. That is technically true, and things worked, and nobody said anything. Besides, back then the regular memcpy was pretty simple and worked fine. Nobody noticed except for David Laight, that is. David has a testing a TLP monitor he was writing for an FPGA, and has been occasionally complaining about how memcpy_toio() writes things one byte at a time. Which is completely unacceptable from a performance standpoint, even if it happens to technically work. The reason it's writing one byte at a time is because while it's technically true that accesses to iomem are the same as accesses to regular memory on x86, the _granularity_ (and ordering) of accesses matter to iomem in ways that they don't matter to regular cached memory. In particular, when ERMS is set, we default to using "rep movsb" for larger memory copies. That is indeed perfectly fine for real memory, since the whole point is that the CPU is going to do cacheline optimizations and executes the memory copy efficiently for cached memory. With iomem? Not so much. With iomem, "rep movsb" will indeed work, but it will copy things one byte at a time. Slowly and ponderously. Now, originally, back in 2010 when commit 6175ddf0 was done, we didn't use ERMS, and this was much less noticeable. Our normal memcpy() was simpler in other ways too. Because in fact, it's not just about using the string instructions. Our memcpy() these days does things like "read and write overlapping values" to handle the last bytes of the copy. Again, for normal memory, overlapping accesses isn't an issue. For iomem? It can be. So this re-introduces the specialized memcpy_toio(), memcpy_fromio() and memset_io() functions. It doesn't particularly optimize them, but it tries to at least not be horrid, or do overlapping accesses. In fact, this uses the existing __inline_memcpy() function that we still had lying around that uses our very traditional "rep movsl" loop followed by movsw/movsb for the final bytes. Somebody may decide to try to improve on it, but if we've gone almost a decade with only one person really ever noticing and complaining, maybe it's not worth worrying about further, once it's not _completely_ broken? Reported-by:
David Laight <David.Laight@aculab.com> Signed-off-by:
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Linus Torvalds authored
This actually enables the __put_user_goto() functionality in unsafe_put_user(). For an example of the effect of this, this is the code generated for the unsafe_put_user(signo, &infop->si_signo, Efault); in the waitid() system call: movl %ecx,(%rbx) # signo, MEM[(struct __large_struct *)_2] It's just one single store instruction, along with generating an exception table entry pointing to the Efault label case in case that instruction faults. Before, we would generate this: xorl %edx, %edx movl %ecx,(%rbx) # signo, MEM[(struct __large_struct *)_3] testl %edx, %edx jne .L309 with the exception table generated for that 'mov' instruction causing us to jump to a stub that set %edx to -EFAULT and then jumped back to the 'testl' instruction. So not only do we now get rid of the extra code in the normal sequence, we also avoid unnecessarily keeping that extra error register live across it all. Signed-off-by: -
Linus Torvalds authored
This is finally the actual reason for the odd error handling in the "unsafe_get/put_user()" functions, introduced over three years ago. Using a "jump to error label" interface is somewhat odd, but very convenient as a programming interface, and more importantly, it fits very well with simply making the target be the exception handler address directly from the inline asm. The reason it took over three years to actually do this? We need "asm goto" support for it, which only became the default on x86 last year. It's now been a year that we've forced asm goto support (see commit e501ce95 "x86: Force asm-goto"), and so let's just do it here too. [ Side note: this commit was originally done back in 2016. The above commentary about timing is obviously about it only now getting merged into my real upstream tree - Linus ] Sadly, gcc still only supports "asm goto" with asms that do not have any outputs, so we are limited to only the put_user case for this. Maybe in several more years we can do the get_user case too. Signed-off-by:
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- Jan 04, 2019
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Joel Fernandes (Google) authored
Patch series "Add support for fast mremap". This series speeds up the mremap(2) syscall by copying page tables at the PMD level even for non-THP systems. There is concern that the extra 'address' argument that mremap passes to pte_alloc may do something subtle architecture related in the future that may make the scheme not work. Also we find that there is no point in passing the 'address' to pte_alloc since its unused. This patch therefore removes this argument tree-wide resulting in a nice negative diff as well. Also ensuring along the way that the enabled architectures do not do anything funky with the 'address' argument that goes unnoticed by the optimization. Build and boot tested on x86-64. Build tested on arm64. The config enablement patch for arm64 will be posted in the future after more testing. The changes were obtained by applying the following Coccinelle script. (thanks Julia for answering all Coccinelle questions!). Following fix ups were done manually: * Removal of address argument from pte_fragment_alloc * Removal of pte_alloc_one_fast definitions from m68k and microblaze. // Options: --include-headers --no-includes // Note: I split the 'identifier fn' line, so if you are manually // running it, please unsplit it so it runs for you. virtual patch @pte_alloc_func_def depends on patch exists@ identifier E2; identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$"; type T2; @@ fn(... - , T2 E2 ) { ... } @pte_alloc_func_proto_noarg depends on patch exists@ type T1, T2, T3, T4; identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$"; @@ ( - T3 fn(T1, T2); + T3 fn(T1); | - T3 fn(T1, T2, T4); + T3 fn(T1, T2); ) @pte_alloc_func_proto depends on patch exists@ identifier E1, E2, E4; type T1, T2, T3, T4; identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$"; @@ ( - T3 fn(T1 E1, T2 E2); + T3 fn(T1 E1); | - T3 fn(T1 E1, T2 E2, T4 E4); + T3 fn(T1 E1, T2 E2); ) @pte_alloc_func_call depends on patch exists@ expression E2; identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$"; @@ fn(... -, E2 ) @pte_alloc_macro depends on patch exists@ identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$"; identifier a, b, c; expression e; position p; @@ ( - #define fn(a, b, c) e + #define fn(a, b) e | - #define fn(a, b) e + #define fn(a) e ) Link: http://lkml.kernel.org/r/20181108181201.88826-2-joelaf@google.com Signed-off-by:Joel Fernandes (Google) <joel@joelfernandes.org> Suggested-by:
Kirill A. Shutemov <kirill@shutemov.name> Acked-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
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Matthew Wilcox authored
When testing in userspace, UBSAN pointed out that shifting into the sign bit is undefined behaviour. It doesn't really make sense to ask for the highest set bit of a negative value, so just turn the argument type into an unsigned int. Some architectures (eg ppc) already had it declared as an unsigned int, so I don't expect too many problems. Link: http://lkml.kernel.org/r/20181105221117.31828-1-willy@infradead.org Signed-off-by:
Matthew Wilcox <willy@infradead.org> Acked-by:
Geert Uytterhoeven <geert@linux-m68k.org> Cc: <linux-arch@vger.kernel.org> Signed-off-by:
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Linus Torvalds authored
Originally, the rule used to be that you'd have to do access_ok() separately, and then user_access_begin() before actually doing the direct (optimized) user access. But experience has shown that people then decide not to do access_ok() at all, and instead rely on it being implied by other operations or similar. Which makes it very hard to verify that the access has actually been range-checked. If you use the unsafe direct user accesses, hardware features (either SMAP - Supervisor Mode Access Protection - on x86, or PAN - Privileged Access Never - on ARM) do force you to use user_access_begin(). But nothing really forces the range check. By putting the range check into user_access_begin(), we actually force people to do the right thing (tm), and the range check vill be visible near the actual accesses. We have way too long a history of people trying to avoid them. Signed-off-by: -
Linus Torvalds authored
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by:
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- Dec 28, 2018
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Alexey Dobriyan authored
and propagate through down the call stack. Link: http://lkml.kernel.org/r/20181124091411.GC10969@avx2 Signed-off-by:
Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by:
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- Dec 21, 2018
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Robert Hoo authored
Signed-off-by:
Robert Hoo <robert.hu@linux.intel.com> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
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Sean Christopherson authored
____kvm_handle_fault_on_reboot() provides a generic exception fixup handler that is used to cleanly handle faults on VMX/SVM instructions during reboot (or at least try to). If there isn't a reboot in progress, ____kvm_handle_fault_on_reboot() treats any exception as fatal to KVM and invokes kvm_spurious_fault(), which in turn generates a BUG() to get a stack trace and die. When it was originally added by commit 4ecac3fd ("KVM: Handle virtualization instruction #UD faults during reboot"), the "call" to kvm_spurious_fault() was handcoded as PUSH+JMP, where the PUSH'd value is the RIP of the faulting instructing. The PUSH+JMP trickery is necessary because the exception fixup handler code lies outside of its associated function, e.g. right after the function. An actual CALL from the .fixup code would show a slightly bogus stack trace, e.g. an extra "random" function would be inserted into the trace, as the return RIP on the stack would point to no known function (and the unwinder will likely try to guess who owns the RIP). Unfortunately, the JMP was replaced with a CALL when the macro was reworked to not spin indefinitely during reboot (commit b7c4145b "KVM: Don't spin on virt instruction faults during reboot"). This causes the aforementioned behavior where a bogus function is inserted into the stack trace, e.g. my builds like to blame free_kvm_area(). Revert the CALL back to a JMP. The changelog for commit b7c4145b ("KVM: Don't spin on virt instruction faults during reboot") contains nothing that indicates the switch to CALL was deliberate. This is backed up by the fact that the PUSH <insn RIP> was left intact. Note that an alternative to the PUSH+JMP magic would be to JMP back to the "real" code and CALL from there, but that would require adding a JMP in the non-faulting path to avoid calling kvm_spurious_fault() and would add no value, i.e. the stack trace would be the same. Using CALL: ------------[ cut here ]------------ kernel BUG at /home/sean/go/src/kernel.org/linux/arch/x86/kvm/x86.c:356! invalid opcode: 0000 [#1] SMP CPU: 4 PID: 1057 Comm: qemu-system-x86 Not tainted 4.20.0-rc6+ #75 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:kvm_spurious_fault+0x5/0x10 [kvm] Code: <0f> 0b 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 55 49 89 fd 41 RSP: 0018:ffffc900004bbcc8 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffffffffffff RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff888273fd8000 R08: 00000000000003e8 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000784 R12: ffffc90000371fb0 R13: 0000000000000000 R14: 000000026d763cf4 R15: ffff888273fd8000 FS: 00007f3d69691700(0000) GS:ffff888277800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f89bc56fe0 CR3: 0000000271a5a001 CR4: 0000000000362ee0 Call Trace: free_kvm_area+0x1044/0x43ea [kvm_intel] ? vmx_vcpu_run+0x156/0x630 [kvm_intel] ? kvm_arch_vcpu_ioctl_run+0x447/0x1a40 [kvm] ? kvm_vcpu_ioctl+0x368/0x5c0 [kvm] ? kvm_vcpu_ioctl+0x368/0x5c0 [kvm] ? __set_task_blocked+0x38/0x90 ? __set_current_blocked+0x50/0x60 ? __fpu__restore_sig+0x97/0x490 ? do_vfs_ioctl+0xa1/0x620 ? __x64_sys_futex+0x89/0x180 ? ksys_ioctl+0x66/0x70 ? __x64_sys_ioctl+0x16/0x20 ? do_syscall_64+0x4f/0x100 ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 Modules linked in: vhost_net vhost tap kvm_intel kvm irqbypass bridge stp llc ---[ end trace 9775b14b123b1713 ]--- Using JMP: ------------[ cut here ]------------ kernel BUG at /home/sean/go/src/kernel.org/linux/arch/x86/kvm/x86.c:356! invalid opcode: 0000 [#1] SMP CPU: 6 PID: 1067 Comm: qemu-system-x86 Not tainted 4.20.0-rc6+ #75 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:kvm_spurious_fault+0x5/0x10 [kvm] Code: <0f> 0b 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 55 49 89 fd 41 RSP: 0018:ffffc90000497cd0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffffffffffff RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88827058bd40 R08: 00000000000003e8 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000784 R12: ffffc90000369fb0 R13: 0000000000000000 R14: 00000003c8fc6642 R15: ffff88827058bd40 FS: 00007f3d7219e700(0000) GS:ffff888277900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3d64001000 CR3: 0000000271c6b004 CR4: 0000000000362ee0 Call Trace: vmx_vcpu_run+0x156/0x630 [kvm_intel] ? kvm_arch_vcpu_ioctl_run+0x447/0x1a40 [kvm] ? kvm_vcpu_ioctl+0x368/0x5c0 [kvm] ? kvm_vcpu_ioctl+0x368/0x5c0 [kvm] ? __set_task_blocked+0x38/0x90 ? __set_current_blocked+0x50/0x60 ? __fpu__restore_sig+0x97/0x490 ? do_vfs_ioctl+0xa1/0x620 ? __x64_sys_futex+0x89/0x180 ? ksys_ioctl+0x66/0x70 ? __x64_sys_ioctl+0x16/0x20 ? do_syscall_64+0x4f/0x100 ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 Modules linked in: vhost_net vhost tap kvm_intel kvm irqbypass bridge stp llc ---[ end trace f9daedb85ab3ddba ]--- Fixes: b7c4145b ("KVM: Don't spin on virt instruction faults during reboot") Cc: stable@vger.kernel.org Signed-off-by:
Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by:
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Uros Bizjak authored
Recently the minimum required version of binutils was changed to 2.20, which supports all SVM instruction mnemonics. The patch removes all .byte #defines and uses real instruction mnemonics instead. Signed-off-by:
Uros Bizjak <ubizjak@gmail.com> Signed-off-by:
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Lan Tianyu authored
The patch is to make kvm_set_spte_hva() return int and caller can check return value to determine flush tlb or not. Signed-off-by:
Lan Tianyu <Tianyu.Lan@microsoft.com> Acked-by:
Paul Mackerras <paulus@ozlabs.org> Signed-off-by:
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Lan Tianyu authored
Hyper-V provides HvFlushGuestAddressList() hypercall to flush EPT tlb with specified ranges. This patch is to add the hypercall support. Reviewed-by:
Michael Kelley <mikelley@microsoft.com> Signed-off-by:
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Lan Tianyu authored
Add flush range call back in the kvm_x86_ops and platform can use it to register its associated function. The parameter "kvm_tlb_range" accepts a single range and flush list which contains a list of ranges. Signed-off-by:
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Chao Peng authored
Expose Intel Processor Trace to guest only when the PT works in Host-Guest mode. Signed-off-by:
Chao Peng <chao.p.peng@linux.intel.com> Signed-off-by:
Luwei Kang <luwei.kang@intel.com> Signed-off-by:
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Chao Peng authored
Intel Processor Trace virtualization can be work in one of 2 possible modes: a. System-Wide mode (default): When the host configures Intel PT to collect trace packets of the entire system, it can leave the relevant VMX controls clear to allow VMX-specific packets to provide information across VMX transitions. KVM guest will not aware this feature in this mode and both host and KVM guest trace will output to host buffer. b. Host-Guest mode: Host can configure trace-packet generation while in VMX non-root operation for guests and root operation for native executing normally. Intel PT will be exposed to KVM guest in this mode, and the trace output to respective buffer of host and guest. In this mode, tht status of PT will be saved and disabled before VM-entry and restored after VM-exit if trace a virtual machine. Signed-off-by:
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Luwei Kang authored
This adds support for "output to Trace Transport subsystem" capability of Intel PT. It means that PT can output its trace to an MMIO address range rather than system memory buffer. Acked-by:
Song Liu <songliubraving@fb.com> Signed-off-by:
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Luwei Kang authored
Add bit definitions for Intel PT MSRs to support trace output directed to the memeory subsystem and holds a count if packet bytes that have been sent out. These are required by the upcoming PT support in KVM guests for MSRs read/write emulation. Signed-off-by:
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Luwei Kang authored
intel_pt_validate_hw_cap() validates whether a given PT capability is supported by the hardware. It checks the PT capability array which reflects the capabilities of the hardware on which the code is executed. For setting up PT for KVM guests this is not correct as the capability array for the guest can be different from the host array. Provide a new function to check against a given capability array. Acked-by:
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Chao Peng authored
pt_cap_get() is required by the upcoming PT support in KVM guests. Export it and move the capabilites enum to a global header. As a global functions, "pt_*" is already used for ptrace and other things, so it makes sense to use "intel_pt_*" as a prefix. Acked-by:
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Chao Peng authored
The Intel Processor Trace (PT) MSR bit defines are in a private header. The upcoming support for PT virtualization requires these defines to be accessible from KVM code. Move them to the global MSR header file. Reviewed-by:
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- Dec 20, 2018
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Sinan Kaya authored
We are compiling PCI code today for systems with ACPI and no PCI device present. Remove the useless code and reduce the tight dependency. Signed-off-by:
Sinan Kaya <okaya@kernel.org> Acked-by: Bjorn Helgaas <bhelgaas@google.com> # PCI parts Acked-by:
Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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- Dec 19, 2018
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Ingo Molnar authored
This reverts commit 9e1725b4. See this commit for details about the revert: e769742d ("Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"") The conflict resolution for interaction with: 288e4521: ("x86/asm: 'Simplify' GEN_*_RMWcc() macros") was provided by Masahiro Yamada. Conflicts: arch/x86/include/asm/refcount.h Reported-by:
Borislav Petkov <bp@alien8.de> Reviewed-by:
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Ingo Molnar authored
This reverts commit 77f48ec2. See this commit for details about the revert: e769742d ("Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"") Reported-by:
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Ingo Molnar authored
This reverts commit f81f8ad5. See this commit for details about the revert: e769742d ("Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"") Reported-by:
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Ingo Molnar authored
This reverts commit 494b5168. See this commit for details about the revert: e769742d ("Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"") Reported-by:
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Ingo Molnar authored
This reverts commit 0474d5d9. See this commit for details about the revert: e769742d ("Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"") Reported-by:
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Ingo Molnar authored
This reverts commit d5a581d8. See this commit for details about the revert: e769742d ("Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"") Reported-by:
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Ingo Molnar authored
This reverts commit 5bdcd510. The macro based workarounds for GCC's inlining bugs caused regressions: distcc and other distro build setups broke, and the fixes are not easy nor will they solve regressions on already existing installations. So we are reverting this patch and the 8 followup patches. What makes this revert easier is that GCC9 will likely include the new 'asm inline' syntax that makes inlining of assembly blocks a lot more robust. This is a superior method to any macro based hackeries - and might even be backported to GCC8, which would make all modern distros get the inlining fixes as well. Many thanks to Masahiro Yamada and others for helping sort out these problems. Reported-by:
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- Dec 18, 2018
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Eduardo Habkost authored
Some guests OSes (including Windows 10) write to MSR 0xc001102c on some cases (possibly while trying to apply a CPU errata). Make KVM ignore reads and writes to that MSR, so the guest won't crash. The MSR is documented as "Execution Unit Configuration (EX_CFG)", at AMD's "BIOS and Kernel Developer's Guide (BKDG) for AMD Family 15h Models 00h-0Fh Processors". Cc: stable@vger.kernel.org Signed-off-by:
Eduardo Habkost <ehabkost@redhat.com> Signed-off-by:
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Chang S. Bae authored
Andy spotted a regression in the fs/gs base helpers after the patch series was committed. The helper functions which write fs/gs base are not just writing the base, they are also changing the index. That's wrong and needs to be separated because writing the base has not to modify the index. While the regression is not causing any harm right now because the only caller depends on that behaviour, it's a guarantee for subtle breakage down the road. Make the index explicitly changed from the caller, instead of including the code in the helpers. Subsequently, the task write helpers do not handle for the current task anymore. The range check for a base value is also factored out, to minimize code redundancy from the caller. Fixes: b1378a56 ("x86/fsgsbase/64: Introduce FS/GS base helper functions") Suggested-by:
Andy Lutomirski <luto@kernel.org> Signed-off-by:
Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by:
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Thomas Lendacky authored
Different AMD processors may have different implementations of STIBP. When STIBP is conditionally enabled, some implementations would benefit from having STIBP always on instead of toggling the STIBP bit through MSR writes. This preference is advertised through a CPUID feature bit. When conditional STIBP support is requested at boot and the CPU advertises STIBP always-on mode as preferred, switch to STIBP "on" support. To show that this transition has occurred, create a new spectre_v2_user_mitigation value and a new spectre_v2_user_strings message. The new mitigation value is used in spectre_v2_user_select_mitigation() to print the new mitigation message as well as to return a new string from stibp_state(). Signed-off-by:
Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by:
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- Dec 14, 2018
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Marc Orr authored
Previously, the guest_fpu field was embedded in the kvm_vcpu_arch struct. Unfortunately, the field is quite large, (e.g., 4352 bytes on my current setup). This bloats the kvm_vcpu_arch struct for x86 into an order 3 memory allocation, which can become a problem on overcommitted machines. Thus, this patch moves the fpu state outside of the kvm_vcpu_arch struct. With this patch applied, the kvm_vcpu_arch struct is reduced to 15168 bytes for vmx on my setup when building the kernel with kvmconfig. Suggested-by:
Dave Hansen <dave.hansen@intel.com> Signed-off-by:
Marc Orr <marcorr@google.com> Signed-off-by:
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Marc Orr authored
Previously, x86's instantiation of 'struct kvm_vcpu_arch' added an fpu field to save/restore fpu-related architectural state, which will differ from kvm's fpu state. However, this is redundant to the 'struct fpu' field, called fpu, embedded in the task struct, via the thread field. Thus, this patch removes the user_fpu field from the kvm_vcpu_arch struct and replaces it with the task struct's fpu field. This change is significant because the fpu struct is actually quite large. For example, on the system used to develop this patch, this change reduces the size of the vcpu_vmx struct from 23680 bytes down to 19520 bytes, when building the kernel with kvmconfig. This reduction in the size of the vcpu_vmx struct moves us closer to being able to allocate the struct at order 2, rather than order 3. Suggested-by:
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