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2017-09-04Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm changes from Ingo Molnar: "PCID support, 5-level paging support, Secure Memory Encryption support The main changes in this cycle are support for three new, complex hardware features of x86 CPUs: - Add 5-level paging support, which is a new hardware feature on upcoming Intel CPUs allowing up to 128 PB of virtual address space and 4 PB of physical RAM space - a 512-fold increase over the old limits. (Supercomputers of the future forecasting hurricanes on an ever warming planet can certainly make good use of more RAM.) Many of the necessary changes went upstream in previous cycles, v4.14 is the first kernel that can enable 5-level paging. This feature is activated via CONFIG_X86_5LEVEL=y - disabled by default. (By Kirill A. Shutemov) - Add 'encrypted memory' support, which is a new hardware feature on upcoming AMD CPUs ('Secure Memory Encryption', SME) allowing system RAM to be encrypted and decrypted (mostly) transparently by the CPU, with a little help from the kernel to transition to/from encrypted RAM. Such RAM should be more secure against various attacks like RAM access via the memory bus and should make the radio signature of memory bus traffic harder to intercept (and decrypt) as well. This feature is activated via CONFIG_AMD_MEM_ENCRYPT=y - disabled by default. (By Tom Lendacky) - Enable PCID optimized TLB flushing on newer Intel CPUs: PCID is a hardware feature that attaches an address space tag to TLB entries and thus allows to skip TLB flushing in many cases, even if we switch mm's. (By Andy Lutomirski) All three of these features were in the works for a long time, and it's coincidence of the three independent development paths that they are all enabled in v4.14 at once" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (65 commits) x86/mm: Enable RCU based page table freeing (CONFIG_HAVE_RCU_TABLE_FREE=y) x86/mm: Use pr_cont() in dump_pagetable() x86/mm: Fix SME encryption stack ptr handling kvm/x86: Avoid clearing the C-bit in rsvd_bits() x86/CPU: Align CR3 defines x86/mm, mm/hwpoison: Clear PRESENT bit for kernel 1:1 mappings of poison pages acpi, x86/mm: Remove encryption mask from ACPI page protection type x86/mm, kexec: Fix memory corruption with SME on successive kexecs x86/mm/pkeys: Fix typo in Documentation/x86/protection-keys.txt x86/mm/dump_pagetables: Speed up page tables dump for CONFIG_KASAN=y x86/mm: Implement PCID based optimization: try to preserve old TLB entries using PCID x86: Enable 5-level paging support via CONFIG_X86_5LEVEL=y x86/mm: Allow userspace have mappings above 47-bit x86/mm: Prepare to expose larger address space to userspace x86/mpx: Do not allow MPX if we have mappings above 47-bit x86/mm: Rename tasksize_32bit/64bit to task_size_32bit/64bit() x86/xen: Redefine XEN_ELFNOTE_INIT_P2M using PUD_SIZE * PTRS_PER_PUD x86/mm/dump_pagetables: Fix printout of p4d level x86/mm/dump_pagetables: Generalize address normalization x86/boot: Fix memremap() related build failure ...
2017-09-04Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Ingo Molnar: - Introduce the ORC unwinder, which can be enabled via CONFIG_ORC_UNWINDER=y. The ORC unwinder is a lightweight, Linux kernel specific debuginfo implementation, which aims to be DWARF done right for unwinding. Objtool is used to generate the ORC unwinder tables during build, so the data format is flexible and kernel internal: there's no dependency on debuginfo created by an external toolchain. The ORC unwinder is almost two orders of magnitude faster than the (out of tree) DWARF unwinder - which is important for perf call graph profiling. It is also significantly simpler and is coded defensively: there has not been a single ORC related kernel crash so far, even with early versions. (knock on wood!) But the main advantage is that enabling the ORC unwinder allows CONFIG_FRAME_POINTERS to be turned off - which speeds up the kernel measurably: With frame pointers disabled, GCC does not have to add frame pointer instrumentation code to every function in the kernel. The kernel's .text size decreases by about 3.2%, resulting in better cache utilization and fewer instructions executed, resulting in a broad kernel-wide speedup. Average speedup of system calls should be roughly in the 1-3% range - measurements by Mel Gorman [1] have shown a speedup of 5-10% for some function execution intense workloads. The main cost of the unwinder is that the unwinder data has to be stored in RAM: the memory cost is 2-4MB of RAM, depending on kernel config - which is a modest cost on modern x86 systems. Given how young the ORC unwinder code is it's not enabled by default - but given the performance advantages the plan is to eventually make it the default unwinder on x86. See Documentation/x86/orc-unwinder.txt for more details. - Remove lguest support: its intended role was that of a temporary proof of concept for virtualization, plus its removal will enable the reduction (removal) of the paravirt API as well, so Rusty agreed to its removal. (Juergen Gross) - Clean up and fix FSGS related functionality (Andy Lutomirski) - Clean up IO access APIs (Andy Shevchenko) - Enhance the symbol namespace (Jiri Slaby) * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits) objtool: Handle GCC stack pointer adjustment bug x86/entry/64: Use ENTRY() instead of ALIGN+GLOBAL for stub32_clone() x86/fpu/math-emu: Add ENDPROC to functions x86/boot/64: Extract efi_pe_entry() from startup_64() x86/boot/32: Extract efi_pe_entry() from startup_32() x86/lguest: Remove lguest support x86/paravirt/xen: Remove xen_patch() objtool: Fix objtool fallthrough detection with function padding x86/xen/64: Fix the reported SS and CS in SYSCALL objtool: Track DRAP separately from callee-saved registers objtool: Fix validate_branch() return codes x86: Clarify/fix no-op barriers for text_poke_bp() x86/switch_to/64: Rewrite FS/GS switching yet again to fix AMD CPUs selftests/x86/fsgsbase: Test selectors 1, 2, and 3 x86/fsgsbase/64: Report FSBASE and GSBASE correctly in core dumps x86/fsgsbase/64: Fully initialize FS and GS state in start_thread_common x86/asm: Fix UNWIND_HINT_REGS macro for older binutils x86/asm/32: Fix regs_get_register() on segment registers x86/xen/64: Rearrange the SYSCALL entries x86/asm/32: Remove a bunch of '& 0xffff' from pt_regs segment reads ...
2017-08-31KVM: update to new mmu_notifier semantic v2Jérôme Glisse
Calls to mmu_notifier_invalidate_page() were replaced by calls to mmu_notifier_invalidate_range() and are now bracketed by calls to mmu_notifier_invalidate_range_start()/end() Remove now useless invalidate_page callback. Changed since v1 (Linus Torvalds) - remove now useless kvm_arch_mmu_notifier_invalidate_page() Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Tested-by: Mike Galbraith <efault@gmx.de> Tested-by: Adam Borowski <kilobyte@angband.pl> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: kvm@vger.kernel.org Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-08-29x86/idt: Unify gate_struct handling for 32/64-bit kernelsThomas Gleixner
The first 32 bits of gate struct are the same for 32 and 64 bit kernels. The 32-bit version uses desc_struct and no designated data structure, so we need different accessors for 32 and 64 bit kernels. Aside of that the macros which are necessary to build the 32-bit gate descriptor are horrible to read. Unify the gate structs and switch all code fiddling with it over. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20170828064957.861974317@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-29Merge branch 'linus' into x86/apic, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-26kvm/x86: Avoid clearing the C-bit in rsvd_bits()Brijesh Singh
The following commit: d0ec49d4de90 ("kvm/x86/svm: Support Secure Memory Encryption within KVM") uses __sme_clr() to remove the C-bit in rsvd_bits(). rsvd_bits() is just a simple function to return some 1 bits. Applying a mask based on properties of the host MMU is incorrect. Additionally, the masks computed by __reset_rsvds_bits_mask also apply to guest page tables, where the C bit is reserved since we don't emulate SME. The fix is to clear the C-bit from rsvd_bits_mask array after it has been populated from __reset_rsvds_bits_mask() Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: kvm@vger.kernel.org Cc: paolo.bonzini@gmail.com Fixes: d0ec49d ("kvm/x86/svm: Support Secure Memory Encryption within KVM") Link: http://lkml.kernel.org/r/20170825205540.123531-1-brijesh.singh@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-26Merge branch 'linus' into x86/mm to pick up fixes and to fix conflictsIngo Molnar
Conflicts: arch/x86/kernel/head64.c arch/x86/mm/mmap.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-25kvm: nVMX: Validate the virtual-APIC address on nested VM-entryJim Mattson
According to the SDM, if the "use TPR shadow" VM-execution control is 1, bits 11:0 of the virtual-APIC address must be 0 and the address should set any bits beyond the processor's physical-address width. Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-25KVM, pkeys: do not use PKRU value in vcpu->arch.guest_fpu.statePaolo Bonzini
The host pkru is restored right after vcpu exit (commit 1be0e61), so KVM_GET_XSAVE will return the host PKRU value instead. Fix this by using the guest PKRU explicitly in fill_xsave and load_xsave. This part is based on a patch by Junkang Fu. The host PKRU data may also not match the value in vcpu->arch.guest_fpu.state, because it could have been changed by userspace since the last time it was saved, so skip loading it in kvm_load_guest_fpu. Reported-by: Junkang Fu <junkang.fjk@alibaba-inc.com> Cc: Yang Zhang <zy107165@alibaba-inc.com> Fixes: 1be0e61c1f255faaeab04a390e00c8b9b9042870 Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-25KVM: x86: simplify handling of PKRUPaolo Bonzini
Move it to struct kvm_arch_vcpu, replacing guest_pkru_valid with a simple comparison against the host value of the register. The write of PKRU in addition can be skipped if the guest has not enabled the feature. Once we do this, we need not test OSPKE in the host anymore, because guest_CR4.PKE=1 implies host_CR4.PKE=1. The static PKU test is kept to elide the code on older CPUs. Suggested-by: Yang Zhang <zy107165@alibaba-inc.com> Fixes: 1be0e61c1f255faaeab04a390e00c8b9b9042870 Cc: stable@vger.kernel.org Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-25KVM: x86: block guest protection keys unless the host has them enabledPaolo Bonzini
If the host has protection keys disabled, we cannot read and write the guest PKRU---RDPKRU and WRPKRU fail with #GP(0) if CR4.PKE=0. Block the PKU cpuid bit in that case. This ensures that guest_CR4.PKE=1 implies host_CR4.PKE=1. Fixes: 1be0e61c1f255faaeab04a390e00c8b9b9042870 Cc: stable@vger.kernel.org Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-25Merge branch 'x86/asm' into x86/apicThomas Gleixner
Pick up dependent changes to avoid merge conflicts
2017-08-24KVM: nVMX: Fix trying to cancel vmlauch/vmresumeWanpeng Li
------------[ cut here ]------------ WARNING: CPU: 7 PID: 3861 at /home/kernel/ssd/kvm/arch/x86/kvm//vmx.c:11299 nested_vmx_vmexit+0x176e/0x1980 [kvm_intel] CPU: 7 PID: 3861 Comm: qemu-system-x86 Tainted: G W OE 4.13.0-rc4+ #11 RIP: 0010:nested_vmx_vmexit+0x176e/0x1980 [kvm_intel] Call Trace: ? kvm_multiple_exception+0x149/0x170 [kvm] ? handle_emulation_failure+0x79/0x230 [kvm] ? load_vmcs12_host_state+0xa80/0xa80 [kvm_intel] ? check_chain_key+0x137/0x1e0 ? reexecute_instruction.part.168+0x130/0x130 [kvm] nested_vmx_inject_exception_vmexit+0xb7/0x100 [kvm_intel] ? nested_vmx_inject_exception_vmexit+0xb7/0x100 [kvm_intel] vmx_queue_exception+0x197/0x300 [kvm_intel] kvm_arch_vcpu_ioctl_run+0x1b0c/0x2c90 [kvm] ? kvm_arch_vcpu_runnable+0x220/0x220 [kvm] ? preempt_count_sub+0x18/0xc0 ? restart_apic_timer+0x17d/0x300 [kvm] ? kvm_lapic_restart_hv_timer+0x37/0x50 [kvm] ? kvm_arch_vcpu_load+0x1d8/0x350 [kvm] kvm_vcpu_ioctl+0x4e4/0x910 [kvm] ? kvm_vcpu_ioctl+0x4e4/0x910 [kvm] ? kvm_dev_ioctl+0xbe0/0xbe0 [kvm] The flag "nested_run_pending", which can override the decision of which should run next, L1 or L2. nested_run_pending=1 means that we *must* run L2 next, not L1. This is necessary in particular when L1 did a VMLAUNCH of L2 and therefore expects L2 to be run (and perhaps be injected with an event it specified, etc.). Nested_run_pending is especially intended to avoid switching to L1 in the injection decision-point. This can be handled just like the other cases in vmx_check_nested_events, instead of having a special case in vmx_queue_exception. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-24KVM: X86: Fix loss of exception which has not yet been injectedWanpeng Li
vmx_complete_interrupts() assumes that the exception is always injected, so it can be dropped by kvm_clear_exception_queue(). However, an exception cannot be injected immediately if it is: 1) originally destined to a nested guest; 2) trapped to cause a vmexit; 3) happening right after VMLAUNCH/VMRESUME, i.e. when nested_run_pending is true. This patch applies to exceptions the same algorithm that is used for NMIs, replacing exception.reinject with "exception.injected" (equivalent to nmi_injected). exception.pending now represents an exception that is queued and whose side effects (e.g., update RFLAGS.RF or DR7) have not been applied yet. If exception.pending is true, the exception might result in a nested vmexit instead, too (in which case the side effects must not be applied). exception.injected instead represents an exception that is going to be injected into the guest at the next vmentry. Reported-by: Radim Krčmář <rkrcmar@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-24KVM: VMX: use kvm_event_needs_reinjectionWanpeng Li
Use kvm_event_needs_reinjection() encapsulation. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-24KVM: MMU: speedup update_permission_bitmaskPaolo Bonzini
update_permission_bitmask currently does a 128-iteration loop to, essentially, compute a constant array. Computing the 8 bits in parallel reduces it to 16 iterations, and is enough to speed it up substantially because many boolean operations in the inner loop become constants or simplify noticeably. Because update_permission_bitmask is actually the top item in the profile for nested vmexits, this speeds up an L2->L1 vmexit by about ten thousand clock cycles, or up to 30%: before after cpuid 35173 25954 vmcall 35122 27079 inl_from_pmtimer 52635 42675 inl_from_qemu 53604 44599 inl_from_kernel 38498 30798 outl_to_kernel 34508 28816 wr_tsc_adjust_msr 34185 26818 rd_tsc_adjust_msr 37409 27049 mmio-no-eventfd:pci-mem 50563 45276 mmio-wildcard-eventfd:pci-mem 34495 30823 mmio-datamatch-eventfd:pci-mem 35612 31071 portio-no-eventfd:pci-io 44925 40661 portio-wildcard-eventfd:pci-io 29708 27269 portio-datamatch-eventfd:pci-io 31135 27164 (I wrote a small C program to compare the tables for all values of CR0.WP, CR4.SMAP and CR4.SMEP, and they match). Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-24KVM: MMU: Expose the LA57 feature to VM.Yu Zhang
This patch exposes 5 level page table feature to the VM. At the same time, the canonical virtual address checking is extended to support both 48-bits and 57-bits address width. Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-24KVM: MMU: Add 5 level EPT & Shadow page table support.Yu Zhang
Extends the shadow paging code, so that 5 level shadow page table can be constructed if VM is running in 5 level paging mode. Also extends the ept code, so that 5 level ept table can be constructed if maxphysaddr of VM exceeds 48 bits. Unlike the shadow logic, KVM should still use 4 level ept table for a VM whose physical address width is less than 48 bits, even when the VM is running in 5 level paging mode. Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com> [Unconditionally reset the MMU context in kvm_cpuid_update. Changing MAXPHYADDR invalidates the reserved bit bitmasks. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-24KVM: MMU: Rename PT64_ROOT_LEVEL to PT64_ROOT_4LEVEL.Yu Zhang
Now we have 4 level page table and 5 level page table in 64 bits long mode, let's rename the PT64_ROOT_LEVEL to PT64_ROOT_4LEVEL, then we can use PT64_ROOT_5LEVEL for 5 level page table, it's helpful to make the code more clear. Also PT64_ROOT_MAX_LEVEL is defined as 4, so that we can just redefine it to 5 whenever a replacement is needed for 5 level paging. Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-24KVM: MMU: check guest CR3 reserved bits based on its physical address width.Yu Zhang
Currently, KVM uses CR3_L_MODE_RESERVED_BITS to check the reserved bits in CR3. Yet the length of reserved bits in guest CR3 should be based on the physical address width exposed to the VM. This patch changes CR3 check logic to calculate the reserved bits at runtime. Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-24KVM: x86: Add return value to kvm_cpuid().Yu Zhang
Return false in kvm_cpuid() when it fails to find the cpuid entry. Also, this routine(and its caller) is optimized with a new argument - check_limit, so that the check_cpuid_limit() fall back can be avoided. Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-24kvm: vmx: Raise #UD on unsupported XSAVES/XRSTORSPaolo Bonzini
A guest may not be configured to support XSAVES/XRSTORS, even when the host does. If the guest does not support XSAVES/XRSTORS, clear the secondary execution control so that the processor will raise #UD. Also clear the "allowed-1" bit for XSAVES/XRSTORS exiting in the IA32_VMX_PROCBASED_CTLS2 MSR, and pass through VMCS12's control in the VMCS02. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-24kvm: vmx: Raise #UD on unsupported RDSEEDJim Mattson
A guest may not be configured to support RDSEED, even when the host does. If the guest does not support RDSEED, intercept the instruction and synthesize #UD. Also clear the "allowed-1" bit for RDSEED exiting in the IA32_VMX_PROCBASED_CTLS2 MSR. Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-24kvm: vmx: Raise #UD on unsupported RDRANDJim Mattson
A guest may not be configured to support RDRAND, even when the host does. If the guest does not support RDRAND, intercept the instruction and synthesize #UD. Also clear the "allowed-1" bit for RDRAND exiting in the IA32_VMX_PROCBASED_CTLS2 MSR. Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-24KVM: VMX: cache secondary exec controlsPaolo Bonzini
Currently, secondary execution controls are divided in three groups: - static, depending mostly on the module arguments or the processor (vmx_secondary_exec_control) - static, depending on CPUID (vmx_cpuid_update) - dynamic, depending on nested VMX or local APIC state Because walking CPUID is expensive, prepare_vmcs02 is using only the first group. This however is unnecessarily complicated. Just cache the static secondary execution controls, and then prepare_vmcs02 does not need to compute them every time. Computation of all static secondary execution controls is now kept in a single function, vmx_compute_secondary_exec_control. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-24x86/lguest: Remove lguest supportJuergen Gross
Lguest seems to be rather unused these days. It has seen only patches ensuring it still builds the last two years and its official state is "Odd Fixes". Remove it in order to be able to clean up the paravirt code. Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: boris.ostrovsky@oracle.com Cc: lguest@lists.ozlabs.org Cc: rusty@rustcorp.com.au Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/20170816173157.8633-3-jgross@suse.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-23KVM: SVM: Enable Virtual GIF featureJanakarajan Natarajan
Enable the Virtual GIF feature. This is done by setting bit 25 at position 60h in the vmcb. With this feature enabled, the processor uses bit 9 at position 60h as the virtual GIF when executing STGI/CLGI instructions. Since the execution of STGI by the L1 hypervisor does not cause a return to the outermost (L0) hypervisor, the enable_irq_window and enable_nmi_window are modified. The IRQ window will be opened even if GIF is not set, under the assumption that on resuming the L1 hypervisor the IRQ will be held pending until the processor executes the STGI instruction. For the NMI window, the STGI intercept is set. This will assist in opening the window only when GIF=1. Signed-off-by: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-18KVM: VMX: always require WB memory type for EPTDavid Hildenbrand
We already always set that type but don't check if it is supported. Also for nVMX, we only support WB for now. Let's just require it. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-08-18KVM: VMX: cleanup EPTP definitionsDavid Hildenbrand
Don't use shifts, tag them correctly as EPTP and use better matching names (PWL vs. GAW). Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-08-18KVM: SVM: delete avic_vm_id_bitmap (2 megabyte static array)Denys Vlasenko
With lightly tweaked defconfig: text data bss dec hex filename 11259661 5109408 2981888 19350957 12745ad vmlinux.before 11259661 5109408 884736 17253805 10745ad vmlinux.after Only compile-tested. Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: pbonzini@redhat.com Cc: rkrcmar@redhat.com Cc: tglx@linutronix.de Cc: mingo@redhat.com Cc: hpa@zytor.com Cc: x86@kernel.org Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-08-18KVM: x86: fix use of L1 MMIO areas in nested guestsPaolo Bonzini
There is currently some confusion between nested and L1 GPAs. The assignment to "direct" in kvm_mmu_page_fault tries to fix that, but it is not enough. What this patch does is fence off the MMIO cache completely when using shadow nested page tables, since we have neither a GVA nor an L1 GPA to put in the cache. This also allows some simplifications in kvm_mmu_page_fault and FNAME(page_fault). The EPT misconfig likewise does not have an L1 GPA to pass to kvm_io_bus_write, so that must be skipped for guest mode. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> [Changed comment to say "GPAs" instead of "L1's physical addresses", as per David's review. - Radim] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-08-18KVM: x86: Avoid guest page table walk when gpa_available is setBrijesh Singh
When a guest causes a page fault which requires emulation, the vcpu->arch.gpa_available flag is set to indicate that cr2 contains a valid GPA. Currently, emulator_read_write_onepage() makes use of gpa_available flag to avoid a guest page walk for a known MMIO regions. Lets not limit the gpa_available optimization to just MMIO region. The patch extends the check to avoid page walk whenever gpa_available flag is set. Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> [Fix EPT=0 according to Wanpeng Li's fix, plus ensure VMX also uses the new code. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> [Moved "ret < 0" to the else brach, as per David's review. - Radim] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-08-18KVM: x86: simplify ept_misconfigPaolo Bonzini
Calling handle_mmio_page_fault() has been unnecessary since commit e9ee956e311d ("KVM: x86: MMU: Move handle_mmio_page_fault() call to kvm_mmu_page_fault()", 2016-02-22). handle_mmio_page_fault() can now be made static. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-08-11kvm: x86: Disallow illegal IA32_APIC_BASE MSR valuesJim Mattson
Host-initiated writes to the IA32_APIC_BASE MSR do not have to follow local APIC state transition constraints, but the value written must be valid. Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-11KVM: MMU: Bail out immediately if there is no available mmu pageWanpeng Li
Bailing out immediately if there is no available mmu page to alloc. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-11KVM: MMU: Fix softlockup due to mmu_lock is held too longWanpeng Li
watchdog: BUG: soft lockup - CPU#5 stuck for 22s! [warn_test:3089] irq event stamp: 20532 hardirqs last enabled at (20531): [<ffffffff8e9b6908>] restore_regs_and_iret+0x0/0x1d hardirqs last disabled at (20532): [<ffffffff8e9b7ae8>] apic_timer_interrupt+0x98/0xb0 softirqs last enabled at (8266): [<ffffffff8e9badc6>] __do_softirq+0x206/0x4c1 softirqs last disabled at (8253): [<ffffffff8e083918>] irq_exit+0xf8/0x100 CPU: 5 PID: 3089 Comm: warn_test Tainted: G OE 4.13.0-rc3+ #8 RIP: 0010:kvm_mmu_prepare_zap_page+0x72/0x4b0 [kvm] Call Trace: make_mmu_pages_available.isra.120+0x71/0xc0 [kvm] kvm_mmu_load+0x1cf/0x410 [kvm] kvm_arch_vcpu_ioctl_run+0x1316/0x1bf0 [kvm] kvm_vcpu_ioctl+0x340/0x700 [kvm] ? kvm_vcpu_ioctl+0x340/0x700 [kvm] ? __fget+0xfc/0x210 do_vfs_ioctl+0xa4/0x6a0 ? __fget+0x11d/0x210 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x23/0xc2 ? __this_cpu_preempt_check+0x13/0x20 This can be reproduced readily by ept=N and running syzkaller tests since many syzkaller testcases don't setup any memory regions. However, if ept=Y rmode identity map will be created, then kvm_mmu_calculate_mmu_pages() will extend the number of VM's mmu pages to at least KVM_MIN_ALLOC_MMU_PAGES which just hide the issue. I saw the scenario kvm->arch.n_max_mmu_pages == 0 && kvm->arch.n_used_mmu_pages == 1, so there is one active mmu page on the list, kvm_mmu_prepare_zap_page() fails to zap any pages, however prepare_zap_oldest_mmu_page() always returns true. It incurs infinite loop in make_mmu_pages_available() which causes mmu->lock softlockup. This patch fixes it by setting the return value of prepare_zap_oldest_mmu_page() according to whether or not there is mmu page zapped. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-11KVM: nVMX: validate eptp pointerDavid Hildenbrand
Let's reuse the function introduced with eptp switching. We don't explicitly have to check against enable_ept_ad_bits, as this is implicitly done when checking against nested_vmx_ept_caps in valid_ept_address(). Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-11x86/cpufeature, kvm/svm: Rename (shorten) the new "virtualized ↵Borislav Petkov
VMSAVE/VMLOAD" CPUID flag "virtual_vmload_vmsave" is what is going to land in /proc/cpuinfo now as per v4.13-rc4, for a single feature bit which is clearly too long. So rename it to what it is called in the processor manual. "v_vmsave_vmload" is a bit shorter, after all. We could go more aggressively here but having it the same as in the processor manual is advantageous. Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Radim Krčmář <rkrcmar@redhat.com> Cc: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com> Cc: Jörg Rödel <joro@8bytes.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm-ML <kvm@vger.kernel.org> Link: http://lkml.kernel.org/r/20170801185552.GA3743@nazgul.tnic Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-10kvm: nVMX: Add support for fast unprotection of nested guest page tablesPaolo Bonzini
This is the same as commit 147277540bbc ("kvm: svm: Add support for additional SVM NPF error codes", 2016-11-23), but for Intel processors. In this case, the exit qualification field's bit 8 says whether the EPT violation occurred while translating the guest's final physical address or rather while translating the guest page tables. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-10KVM: SVM: Limit PFERR_NESTED_GUEST_PAGE error_code check to L1 guestBrijesh Singh
Commit 147277540bbc ("kvm: svm: Add support for additional SVM NPF error codes", 2016-11-23) added a new error code to aid nested page fault handling. The commit unprotects (kvm_mmu_unprotect_page) the page when we get a NPF due to guest page table walk where the page was marked RO. However, if an L0->L2 shadow nested page table can also be marked read-only when a page is read only in L1's nested page table. If such a page is accessed by L2 while walking page tables it can cause a nested page fault (page table walks are write accesses). However, after kvm_mmu_unprotect_page we may get another page fault, and again in an endless stream. To cover this use case, we qualify the new error_code check with vcpu->arch.mmu_direct_map so that the error_code check would run on L1 guest, and not the L2 guest. This avoids hitting the above scenario. Fixes: 147277540bbc54119172481c8ef6d930cc9fbfc2 Cc: stable@vger.kernel.org Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Thomas Lendacky <thomas.lendacky@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-10KVM: X86: Fix residual mmio emulation request to userspaceWanpeng Li
Reported by syzkaller: The kvm-intel.unrestricted_guest=0 WARNING: CPU: 5 PID: 1014 at /home/kernel/data/kvm/arch/x86/kvm//x86.c:7227 kvm_arch_vcpu_ioctl_run+0x38b/0x1be0 [kvm] CPU: 5 PID: 1014 Comm: warn_test Tainted: G W OE 4.13.0-rc3+ #8 RIP: 0010:kvm_arch_vcpu_ioctl_run+0x38b/0x1be0 [kvm] Call Trace: ? put_pid+0x3a/0x50 ? rcu_read_lock_sched_held+0x79/0x80 ? kmem_cache_free+0x2f2/0x350 kvm_vcpu_ioctl+0x340/0x700 [kvm] ? kvm_vcpu_ioctl+0x340/0x700 [kvm] ? __fget+0xfc/0x210 do_vfs_ioctl+0xa4/0x6a0 ? __fget+0x11d/0x210 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x23/0xc2 ? __this_cpu_preempt_check+0x13/0x20 The syszkaller folks reported a residual mmio emulation request to userspace due to vm86 fails to emulate inject real mode interrupt(fails to read CS) and incurs a triple fault. The vCPU returns to userspace with vcpu->mmio_needed == true and KVM_EXIT_SHUTDOWN exit reason. However, the syszkaller testcase constructs several threads to launch the same vCPU, the thread which lauch this vCPU after the thread whichs get the vcpu->mmio_needed == true and KVM_EXIT_SHUTDOWN will trigger the warning. #define _GNU_SOURCE #include <pthread.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/wait.h> #include <sys/types.h> #include <sys/stat.h> #include <sys/mman.h> #include <fcntl.h> #include <unistd.h> #include <linux/kvm.h> #include <stdio.h> int kvmcpu; struct kvm_run *run; void* thr(void* arg) { int res; res = ioctl(kvmcpu, KVM_RUN, 0); printf("ret1=%d exit_reason=%d suberror=%d\n", res, run->exit_reason, run->internal.suberror); return 0; } void test() { int i, kvm, kvmvm; pthread_t th[4]; kvm = open("/dev/kvm", O_RDWR); kvmvm = ioctl(kvm, KVM_CREATE_VM, 0); kvmcpu = ioctl(kvmvm, KVM_CREATE_VCPU, 0); run = (struct kvm_run*)mmap(0, 4096, PROT_READ|PROT_WRITE, MAP_SHARED, kvmcpu, 0); srand(getpid()); for (i = 0; i < 4; i++) { pthread_create(&th[i], 0, thr, 0); usleep(rand() % 10000); } for (i = 0; i < 4; i++) pthread_join(th[i], 0); } int main() { for (;;) { int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { test(); exit(0); } int status; while (waitpid(pid, &status, __WALL) != pid) {} } return 0; } This patch fixes it by resetting the vcpu->mmio_needed once we receive the triple fault to avoid the residue. Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-08KVM: X86: implement the logic for spinlock optimizationLongpeng(Mike)
get_cpl requires vcpu_load, so we must cache the result (whether the vcpu was preempted when its cpl=0) in kvm_vcpu_arch. Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-08KVM: add spinlock optimization frameworkLongpeng(Mike)
If a vcpu exits due to request a user mode spinlock, then the spinlock-holder may be preempted in user mode or kernel mode. (Note that not all architectures trap spin loops in user mode, only AMD x86 and ARM/ARM64 currently do). But if a vcpu exits in kernel mode, then the holder must be preempted in kernel mode, so we should choose a vcpu in kernel mode as a more likely candidate for the lock holder. This introduces kvm_arch_vcpu_in_kernel() to decide whether the vcpu is in kernel-mode when it's preempted. kvm_vcpu_on_spin's new argument says the same of the spinning VCPU. Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-07KVM: x86: use general helpers for some cpuid manipulationRadim Krčmář
Add guest_cpuid_clear() and use it instead of kvm_find_cpuid_entry(). Also replace some uses of kvm_find_cpuid_entry() with guest_cpuid_has(). Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-07KVM: x86: generalize guest_cpuid_has_ helpersRadim Krčmář
This patch turns guest_cpuid_has_XYZ(cpuid) into guest_cpuid_has(cpuid, X86_FEATURE_XYZ), which gets rid of many very similar helpers. When seeing a X86_FEATURE_*, we can know which cpuid it belongs to, but this information isn't in common code, so we recreate it for KVM. Add some BUILD_BUG_ONs to make sure that it runs nicely. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-07KVM: x86: X86_FEATURE_NRIPS is not scattered anymoreRadim Krčmář
bit(X86_FEATURE_NRIPS) is 3 since 2ccd71f1b278 ("x86/cpufeature: Move some of the scattered feature bits to x86_capability"), so we can simplify the code. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-07KVM: nVMX: Emulate EPTP switching for the L1 hypervisorBandan Das
When L2 uses vmfunc, L0 utilizes the associated vmexit to emulate a switching of the ept pointer by reloading the guest MMU. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Bandan Das <bsd@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-08-07KVM: nVMX: Enable VMFUNC for the L1 hypervisorBandan Das
Expose VMFUNC in MSRs and VMCS fields. No actual VMFUNCs are enabled. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Bandan Das <bsd@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-08-07KVM: vmx: Enable VMFUNCsBandan Das
Enable VMFUNC in the secondary execution controls. This simplifies the changes necessary to expose it to nested hypervisors. VMFUNCs still cause #UD when invoked. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Bandan Das <bsd@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-08-07KVM: nVMX: get rid of nested_release_page*David Hildenbrand
Let's also just use the underlying functions directly here. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> [Rebased on top of 9f744c597460 ("KVM: nVMX: do not pin the VMCS12")] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>