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2020-11-11x86/fpu: Make kernel FPU protection RT friendlyThomas Gleixner1-2/+16
Non RT kernels need to protect FPU against preemption and bottom half processing. This is achieved by disabling bottom halfs via local_bh_disable() which implictly disables preemption. On RT kernels this protection mechanism is not sufficient because local_bh_disable() does not disable preemption. It serializes bottom half related processing via a CPU local lock. As bottom halfs are running always in thread context on RT kernels disabling preemption is the proper choice as it implicitly prevents bottom half processing. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201027101349.588965083@linutronix.de
2020-11-11x86/fpu: Simplify fpregs_[un]lock()Thomas Gleixner1-2/+3
There is no point in disabling preemption and then disabling bottom halfs. Just disabling bottom halfs is sufficient as it implicitly disables preemption on !RT kernels. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201027101349.455380473@linutronix.de
2020-11-08Merge tag 'x86-urgent-2020-11-08' of ↵Linus Torvalds5-32/+54
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "A set of x86 fixes: - Use SYM_FUNC_START_WEAK in the mem* ASM functions instead of a combination of .weak and SYM_FUNC_START_LOCAL which makes LLVMs integrated assembler upset - Correct the mitigation selection logic which prevented the related prctl to work correctly - Make the UV5 hubless system work correctly by fixing up the malformed table entries and adding the missing ones" * tag 'x86-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/platform/uv: Recognize UV5 hubless system identifier x86/platform/uv: Remove spaces from OEM IDs x86/platform/uv: Fix missing OEM_TABLE_ID x86/speculation: Allow IBPB to be conditionally enabled on CPUs with always-on STIBP x86/lib: Change .weak to SYM_FUNC_START_WEAK for arch/x86/lib/mem*_64.S
2020-11-07x86/platform/uv: Recognize UV5 hubless system identifierMike Travis1-3/+10
Testing shows a problem in that UV5 hubless systems were not being recognized. Add them to the list of OEM IDs checked. Fixes: 6c7794423a998 ("Add UV5 direct references") Signed-off-by: Mike Travis <mike.travis@hpe.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201105222741.157029-4-mike.travis@hpe.com
2020-11-07x86/platform/uv: Remove spaces from OEM IDsMike Travis1-0/+3
Testing shows that trailing spaces caused problems with the OEM_ID and the OEM_TABLE_ID. One being that the OEM_ID would not string compare correctly. Another the OEM_ID and OEM_TABLE_ID would be concatenated in the printout. Remove any trailing spaces. Fixes: 1e61f5a95f191 ("Add and decode Arch Type in UVsystab") Signed-off-by: Mike Travis <mike.travis@hpe.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201105222741.157029-3-mike.travis@hpe.com
2020-11-07x86/platform/uv: Fix missing OEM_TABLE_IDMike Travis1-2/+5
Testing shows a problem in that the OEM_TABLE_ID was missing for hubless systems. This is used to determine the APIC type (legacy or extended). Add the OEM_TABLE_ID to the early hubless processing. Fixes: 1e61f5a95f191 ("Add and decode Arch Type in UVsystab") Signed-off-by: Mike Travis <mike.travis@hpe.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201105222741.157029-2-mike.travis@hpe.com
2020-11-05x86/speculation: Allow IBPB to be conditionally enabled on CPUs with ↵Anand K Mistry1-18/+33
always-on STIBP On AMD CPUs which have the feature X86_FEATURE_AMD_STIBP_ALWAYS_ON, STIBP is set to on and spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED At the same time, IBPB can be set to conditional. However, this leads to the case where it's impossible to turn on IBPB for a process because in the PR_SPEC_DISABLE case in ib_prctl_set() the spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED condition leads to a return before the task flag is set. Similarly, ib_prctl_get() will return PR_SPEC_DISABLE even though IBPB is set to conditional. More generally, the following cases are possible: 1. STIBP = conditional && IBPB = on for spectre_v2_user=seccomp,ibpb 2. STIBP = on && IBPB = conditional for AMD CPUs with X86_FEATURE_AMD_STIBP_ALWAYS_ON The first case functions correctly today, but only because spectre_v2_user_ibpb isn't updated to reflect the IBPB mode. At a high level, this change does one thing. If either STIBP or IBPB is set to conditional, allow the prctl to change the task flag. Also, reflect that capability when querying the state. This isn't perfect since it doesn't take into account if only STIBP or IBPB is unconditionally on. But it allows the conditional feature to work as expected, without affecting the unconditional one. [ bp: Massage commit message and comment; space out statements for better readability. ] Fixes: 21998a351512 ("x86/speculation: Avoid force-disabling IBPB based on STIBP and enhanced IBRS.") Signed-off-by: Anand K Mistry <amistry@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lkml.kernel.org/r/20201105163246.v2.1.Ifd7243cd3e2c2206a893ad0a5b9a4f19549e22c6@changeid
2020-11-05Merge tag 'hyperv-fixes-signed' of ↵Linus Torvalds1-5/+9
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv fixes from Wei Liu: - clarify a comment (Michael Kelley) - change a pr_warn() to pr_info() (Olaf Hering) * tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: x86/hyperv: Clarify comment on x2apic mode hv_balloon: disable warning when floor reached
2020-11-04x86/lib: Change .weak to SYM_FUNC_START_WEAK for arch/x86/lib/mem*_64.SFangrui Song3-9/+3
Commit 393f203f5fd5 ("x86_64: kasan: add interceptors for memset/memmove/memcpy functions") added .weak directives to arch/x86/lib/mem*_64.S instead of changing the existing ENTRY macros to WEAK. This can lead to the assembly snippet .weak memcpy ... .globl memcpy which will produce a STB_WEAK memcpy with GNU as but STB_GLOBAL memcpy with LLVM's integrated assembler before LLVM 12. LLVM 12 (since https://reviews.llvm.org/D90108) will error on such an overridden symbol binding. Commit ef1e03152cb0 ("x86/asm: Make some functions local") changed ENTRY in arch/x86/lib/memcpy_64.S to SYM_FUNC_START_LOCAL, which was ineffective due to the preceding .weak directive. Use the appropriate SYM_FUNC_START_WEAK instead. Fixes: 393f203f5fd5 ("x86_64: kasan: add interceptors for memset/memmove/memcpy functions") Fixes: ef1e03152cb0 ("x86/asm: Make some functions local") Reported-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Fangrui Song <maskray@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20201103012358.168682-1-maskray@google.com
2020-11-03Merge tag 'x86_seves_for_v5.10_rc3' of ↵Linus Torvalds8-8/+167
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 SEV-ES fixes from Borislav Petkov: "A couple of changes to the SEV-ES code to perform more stringent hypervisor checks before enabling encryption (Joerg Roedel)" * tag 'x86_seves_for_v5.10_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/sev-es: Do not support MMIO to/from encrypted memory x86/head/64: Check SEV encryption before switching to kernel page-table x86/boot/compressed/64: Check SEV encryption in 64-bit boot-path x86/boot/compressed/64: Sanity-check CPUID results in the early #VC handler x86/boot/compressed/64: Introduce sev_status
2020-11-01Merge tag 'x86-urgent-2020-11-01' of ↵Linus Torvalds1-13/+30
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "Three fixes all related to #DB: - Handle the BTF bit correctly so it doesn't get lost due to a kernel #DB - Only clear and set the virtual DR6 value used by ptrace on user space triggered #DB. A kernel #DB must leave it alone to ensure data consistency for ptrace. - Make the bitmasking of the virtual DR6 storage correct so it does not lose DR_STEP" * tag 'x86-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/debug: Fix DR_STEP vs ptrace_get_debugreg(6) x86/debug: Only clear/set ->virtual_dr6 for userspace #DB x86/debug: Fix BTF handling
2020-11-01Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds8-32/+31
Pull kvm fixes from Paolo Bonzini: "ARM: - selftest fix - force PTE mapping on device pages provided via VFIO - fix detection of cacheable mapping at S2 - fallback to PMD/PTE mappings for composite huge pages - fix accounting of Stage-2 PGD allocation - fix AArch32 handling of some of the debug registers - simplify host HYP entry - fix stray pointer conversion on nVHE TLB invalidation - fix initialization of the nVHE code - simplify handling of capabilities exposed to HYP - nuke VCPUs caught using a forbidden AArch32 EL0 x86: - new nested virtualization selftest - miscellaneous fixes - make W=1 fixes - reserve new CPUID bit in the KVM leaves" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: vmx: remove unused variable KVM: selftests: Don't require THP to run tests KVM: VMX: eVMCS: make evmcs_sanitize_exec_ctrls() work again KVM: selftests: test behavior of unmapped L2 APIC-access address KVM: x86: Fix NULL dereference at kvm_msr_ignored_check() KVM: x86: replace static const variables with macros KVM: arm64: Handle Asymmetric AArch32 systems arm64: cpufeature: upgrade hyp caps to final arm64: cpufeature: reorder cpus_have_{const, final}_cap() KVM: arm64: Factor out is_{vhe,nvhe}_hyp_code() KVM: arm64: Force PTE mapping on fault resulting in a device mapping KVM: arm64: Use fallback mapping sizes for contiguous huge page sizes KVM: arm64: Fix masks in stage2_pte_cacheable() KVM: arm64: Fix AArch32 handling of DBGD{CCINT,SCRext} and DBGVCR KVM: arm64: Allocate stage-2 pgd pages with GFP_KERNEL_ACCOUNT KVM: arm64: Drop useless PAN setting on host EL1 to EL2 transition KVM: arm64: Remove leftover kern_hyp_va() in nVHE TLB invalidation KVM: arm64: Don't corrupt tpidr_el2 on failed HVC call x86/kvm: Reserve KVM_FEATURE_MSI_EXT_DEST_ID
2020-10-31KVM: vmx: remove unused variablePaolo Bonzini1-2/+0
Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-31KVM: VMX: eVMCS: make evmcs_sanitize_exec_ctrls() work againVitaly Kuznetsov3-5/+5
It was noticed that evmcs_sanitize_exec_ctrls() is not being executed nowadays despite the code checking 'enable_evmcs' static key looking correct. Turns out, static key magic doesn't work in '__init' section (and it is unclear when things changed) but setup_vmcs_config() is called only once per CPU so we don't really need it to. Switch to checking 'enlightened_vmcs' instead, it is supposed to be in sync with 'enable_evmcs'. Opportunistically make evmcs_sanitize_exec_ctrls '__init' and drop unneeded extra newline from it. Reported-by: Yang Weijiang <weijiang.yang@intel.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20201014143346.2430936-1-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-30KVM: x86: Fix NULL dereference at kvm_msr_ignored_check()Takashi Iwai1-4/+4
The newly introduced kvm_msr_ignored_check() tries to print error or debug messages via vcpu_*() macros, but those may cause Oops when NULL vcpu is passed for KVM_GET_MSRS ioctl. Fix it by replacing the print calls with kvm_*() macros. (Note that this will leave vcpu argument completely unused in the function, but I didn't touch it to make the fix as small as possible. A clean up may be applied later.) Fixes: 12bc2132b15e ("KVM: X86: Do the same ignore_msrs check for feature msrs") BugLink: https://bugzilla.suse.com/show_bug.cgi?id=1178280 Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Message-Id: <20201030151414.20165-1-tiwai@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-30KVM: x86: replace static const variables with macrosPaolo Bonzini3-21/+21
Even though the compiler is able to replace static const variables with their value, it will warn about them being unused when Linux is built with W=1. Use good old macros instead, this is not C++. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-29x86/sev-es: Do not support MMIO to/from encrypted memoryJoerg Roedel1-7/+13
MMIO memory is usually not mapped encrypted, so there is no reason to support emulated MMIO when it is mapped encrypted. Prevent a possible hypervisor attack where a RAM page is mapped as an MMIO page in the nested page-table, so that any guest access to it will trigger a #VC exception and leak the data on that page to the hypervisor via the GHCB (like with valid MMIO). On the read side this attack would allow the HV to inject data into the guest. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lkml.kernel.org/r/20201028164659.27002-6-joro@8bytes.org
2020-10-29x86/head/64: Check SEV encryption before switching to kernel page-tableJoerg Roedel2-0/+17
When SEV is enabled, the kernel requests the C-bit position again from the hypervisor to build its own page-table. Since the hypervisor is an untrusted source, the C-bit position needs to be verified before the kernel page-table is used. Call sev_verify_cbit() before writing the CR3. [ bp: Massage. ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lkml.kernel.org/r/20201028164659.27002-5-joro@8bytes.org
2020-10-29x86/boot/compressed/64: Check SEV encryption in 64-bit boot-pathJoerg Roedel4-0/+96
Check whether the hypervisor reported the correct C-bit when running as an SEV guest. Using a wrong C-bit position could be used to leak sensitive data from the guest to the hypervisor. The check function is in a separate file: arch/x86/kernel/sev_verify_cbit.S so that it can be re-used in the running kernel image. [ bp: Massage. ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lkml.kernel.org/r/20201028164659.27002-4-joro@8bytes.org
2020-10-29x86/boot/compressed/64: Sanity-check CPUID results in the early #VC handlerJoerg Roedel1-0/+26
The early #VC handler which doesn't have a GHCB can only handle CPUID exit codes. It is needed by the early boot code to handle #VC exceptions raised in verify_cpu() and to get the position of the C-bit. But the CPUID information comes from the hypervisor which is untrusted and might return results which trick the guest into the no-SEV boot path with no C-bit set in the page-tables. All data written to memory would then be unencrypted and could leak sensitive data to the hypervisor. Add sanity checks to the early #VC handler to make sure the hypervisor can not pretend that SEV is disabled. [ bp: Massage a bit. ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lkml.kernel.org/r/20201028164659.27002-3-joro@8bytes.org
2020-10-29x86/boot/compressed/64: Introduce sev_statusJoerg Roedel1-1/+15
Introduce sev_status and initialize it together with sme_me_mask to have an indicator which SEV features are enabled. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lkml.kernel.org/r/20201028164659.27002-2-joro@8bytes.org
2020-10-28x86/kvm: Reserve KVM_FEATURE_MSI_EXT_DEST_IDDavid Woodhouse1-0/+1
No functional change; just reserve the feature bit for now so that VMMs can start to implement it. This will allow the host to indicate that MSI emulation supports 15-bit destination IDs, allowing up to 32768 CPUs without interrupt remapping. cf. https://patchwork.kernel.org/patch/11816693/ for qemu Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <4cd59bed05f4b7410d3d1ffd1e997ab53683874d.camel@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-27x86/debug: Fix DR_STEP vs ptrace_get_debugreg(6)Peter Zijlstra1-3/+6
Commit d53d9bc0cf78 ("x86/debug: Change thread.debugreg6 to thread.virtual_dr6") changed the semantics of the variable from random collection of bits, to exactly only those bits that ptrace() needs. Unfortunately this lost DR_STEP for PTRACE_{BLOCK,SINGLE}STEP. Furthermore, it turns out that userspace expects DR_STEP to be unconditionally available, even for manual TF usage outside of PTRACE_{BLOCK,SINGLE}_STEP. Fixes: d53d9bc0cf78 ("x86/debug: Change thread.debugreg6 to thread.virtual_dr6") Reported-by: Kyle Huey <me@kylehuey.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Kyle Huey <me@kylehuey.com> Link: https://lore.kernel.org/r/20201027183330.GM2628@hirez.programming.kicks-ass.net
2020-10-27x86/debug: Only clear/set ->virtual_dr6 for userspace #DBPeter Zijlstra1-6/+6
The ->virtual_dr6 is the value used by ptrace_{get,set}_debugreg(6). A kernel #DB clearing it could mean spurious malfunction of ptrace() expectations. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Kyle Huey <me@kylehuey.com> Link: https://lore.kernel.org/r/20201027093608.028952500@infradead.org
2020-10-27x86/debug: Fix BTF handlingPeter Zijlstra1-7/+21
The SDM states that #DB clears DEBUGCTLMSR_BTF, this means that when the bit is set for userspace (TIF_BLOCKSTEP) and a kernel #DB happens first, the BTF bit meant for userspace execution is lost. Have the kernel #DB handler restore the BTF bit when it was requested for userspace. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Kyle Huey <me@kylehuey.com> Link: https://lore.kernel.org/r/20201027093607.956147736@infradead.org
2020-10-27Merge tag 'x86-urgent-2020-10-27' of ↵Linus Torvalds4-14/+17
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "A couple of x86 fixes which missed rc1 due to my stupidity: - Drop lazy TLB mode before switching to the temporary address space for text patching. text_poke() switches to the temporary mm which clears the lazy mode and restores the original mm afterwards. Due to clearing lazy mode this might restore a already dead mm if exit_mmap() runs in parallel on another CPU. - Document the x32 syscall design fail vs. syscall numbers 512-547 properly. - Fix the ORC unwinder to handle the inactive task frame correctly. This was unearthed due to the slightly different code generation of gcc-10. - Use an up to date screen_info for the boot params of kexec instead of the possibly stale and invalid version which happened to be valid when the kexec kernel was loaded" * tag 'x86-urgent-2020-10-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/alternative: Don't call text_poke() in lazy TLB mode x86/syscalls: Document the fact that syscalls 512-547 are a legacy mistake x86/unwind/orc: Fix inactive tasks with stack pointer in %sp on GCC 10 compiled kernels hyperv_fb: Update screen_info after removing old framebuffer x86/kexec: Use up-to-dated screen_info copy to fill boot params
2020-10-26arch/um: partially revert the conversion to __section() macroLinus Torvalds1-1/+1
A couple of um files ended up not including the header file that defines the __section() macro, and the simplest fix is to just revert the change for those files. Fixes: 33def8498fdd treewide: Convert macro and uses of __section(foo) to __section("foo") Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net> Cc: Joe Perches <joe@perches.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-26Merge branch 'linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 Pull crypto fix from Herbert Xu: "This fixes a regression in x86/poly1305" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: crypto: x86/poly1305 - add back a needed assignment
2020-10-26x86/hyperv: Clarify comment on x2apic modeMichael Kelley1-5/+9
The comment about Hyper-V accessors is unclear regarding their potential use in x2apic mode, as is the associated commit message in e211288b72f1. Clarify that while the architectural and synthetic MSRs are equivalent in x2apic mode, the full set of xapic accessors cannot be used because of register layout differences. Fixes: e211288b72f1 ("x86/hyperv: Make vapic support x2apic mode") Signed-off-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1603723972-81303-1-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-10-25treewide: Convert macro and uses of __section(foo) to __section("foo")Joe Perches18-29/+29
Use a more generic form for __section that requires quotes to avoid complications with clang and gcc differences. Remove the quote operator # from compiler_attributes.h __section macro. Convert all unquoted __section(foo) uses to quoted __section("foo"). Also convert __attribute__((section("foo"))) uses to __section("foo") even if the __attribute__ has multiple list entry forms. Conversion done using the script at: https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl Signed-off-by: Joe Perches <joe@perches.com> Reviewed-by: Nick Desaulniers <ndesaulniers@gooogle.com> Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-25Merge tag 'for-linus-5.10b-rc1c-tag' of ↵Linus Torvalds2-8/+13
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull more xen updates from Juergen Gross: - a series for the Xen pv block drivers adding module parameters for better control of resource usge - a cleanup series for the Xen event driver * tag 'for-linus-5.10b-rc1c-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: Documentation: add xen.fifo_events kernel parameter description xen/events: unmask a fifo event channel only if it was masked xen/events: only register debug interrupt for 2-level events xen/events: make struct irq_info private to events_base.c xen: remove no longer used functions xen-blkfront: Apply changed parameter name to the document xen-blkfront: add a parameter for disabling of persistent grants xen-blkback: add a parameter for disabling of persistent grants
2020-10-24Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds5-9/+6
Pull KVM fixes from Paolo Bonzini: "Two fixes for this merge window, and an unrelated bugfix for a host hang" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: ioapic: break infinite recursion on lazy EOI KVM: vmx: rename pi_init to avoid conflict with paride KVM: x86/mmu: Avoid modulo operator on 64-bit value to fix i386 build
2020-10-24Merge tag 'x86_seves_fixes_for_v5.10_rc1' of ↵Linus Torvalds5-16/+40
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 SEV-ES fixes from Borislav Petkov: "Three fixes to SEV-ES to correct setting up the new early pagetable on 5-level paging machines, to always map boot_params and the kernel cmdline, and disable stack protector for ../compressed/head{32,64}.c. (Arvind Sankar)" * tag 'x86_seves_fixes_for_v5.10_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot/64: Explicitly map boot_params and command line x86/head/64: Disable stack protection for head$(BITS).o x86/boot/64: Initialize 5-level paging variables earlier
2020-10-24KVM: ioapic: break infinite recursion on lazy EOIVitaly Kuznetsov1-4/+1
During shutdown the IOAPIC trigger mode is reset to edge triggered while the vfio-pci INTx is still registered with a resampler. This allows us to get into an infinite loop: ioapic_set_irq -> ioapic_lazy_update_eoi -> kvm_ioapic_update_eoi_one -> kvm_notify_acked_irq -> kvm_notify_acked_gsi -> (via irq_acked fn ptr) irqfd_resampler_ack -> kvm_set_irq -> (via set fn ptr) kvm_set_ioapic_irq -> kvm_ioapic_set_irq -> ioapic_set_irq Commit 8be8f932e3db ("kvm: ioapic: Restrict lazy EOI update to edge-triggered interrupts", 2020-05-04) acknowledges that this recursion loop exists and tries to avoid it at the call to ioapic_lazy_update_eoi, but at this point the scenario is already set, we have an edge interrupt with resampler on the same gsi. Fortunately, the only user of irq ack notifiers (in addition to resamplefd) is i8254 timer interrupt reinjection. These are edge-triggered, so in principle they would need the call to kvm_ioapic_update_eoi_one from ioapic_lazy_update_eoi, but they already disable AVIC(*), so they don't need the lazy EOI behavior. Therefore, remove the call to kvm_ioapic_update_eoi_one from ioapic_lazy_update_eoi. This fixes CVE-2020-27152. Note that this issue cannot happen with SR-IOV assigned devices because virtual functions do not have INTx, only MSI. Fixes: f458d039db7e ("kvm: ioapic: Lazy update IOAPIC EOI") Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Tested-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-24KVM: vmx: rename pi_init to avoid conflict with paridePaolo Bonzini3-4/+4
allyesconfig results in: ld: drivers/block/paride/paride.o: in function `pi_init': (.text+0x1340): multiple definition of `pi_init'; arch/x86/kvm/vmx/posted_intr.o:posted_intr.c:(.init.text+0x0): first defined here make: *** [Makefile:1164: vmlinux] Error 1 because commit: commit 8888cdd0996c2d51cd417f9a60a282c034f3fa28 Author: Xiaoyao Li <xiaoyao.li@intel.com> Date: Wed Sep 23 11:31:11 2020 -0700 KVM: VMX: Extract posted interrupt support to separate files added another pi_init(), though one already existed in the paride code. Reported-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-24KVM: x86/mmu: Avoid modulo operator on 64-bit value to fix i386 buildSean Christopherson1-1/+1
Replace a modulo operator with the more common pattern for computing the gfn "offset" of a huge page to fix an i386 build error. arch/x86/kvm/mmu/tdp_mmu.c:212: undefined reference to `__umoddi3' In fact, almost all of tdp_mmu.c can be elided on 32-bit builds, but that is a much larger patch. Fixes: 2f2fad0897cb ("kvm: x86/mmu: Add functions to handle changed TDP SPTEs") Reported-by: Daniel Díaz <daniel.diaz@linaro.org> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20201024031150.9318-1-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-24crypto: x86/poly1305 - add back a needed assignmentEric Biggers1-0/+1
One of the assignments that was removed by commit 4a0c1de64bf9 ("crypto: x86/poly1305 - Remove assignments with no effect") is actually needed, since it affects the return value. This fixes the following crypto self-test failure: alg: shash: poly1305-simd test failed (wrong result) on test vector 2, cfg="init+update+final aligned buffer" Fixes: 4a0c1de64bf9 ("crypto: x86/poly1305 - Remove assignments with no effect") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-10-23x86/uaccess: fix code generation in put_user()Rasmus Villemoes1-1/+9
Quoting https://gcc.gnu.org/onlinedocs/gcc/Local-Register-Variables.html: You can define a local register variable and associate it with a specified register... The only supported use for this feature is to specify registers for input and output operands when calling Extended asm (see Extended Asm). This may be necessary if the constraints for a particular machine don't provide sufficient control to select the desired register. On 32-bit x86, this is used to ensure that gcc will put an 8-byte value into the %edx:%eax pair, while all other cases will just use the single register %eax (%rax on x86-64). While the _ASM_AX actually just expands to "%eax", note this comment next to get_user() which does something very similar: * The use of _ASM_DX as the register specifier is a bit of a * simplification, as gcc only cares about it as the starting point * and not size: for a 64-bit value it will use %ecx:%edx on 32 bits * (%ecx being the next register in gcc's x86 register sequence), and * %rdx on 64 bits. However, getting this to work requires that there is no code between the assignment to the local register variable and its use as an input to the asm() which can possibly clobber any of the registers involved - including evaluation of the expressions making up other inputs. In the current code, the ptr expression used directly as an input may cause such code to be emitted. For example, Sean Christopherson observed that with KASAN enabled and ptr being current->set_child_tid (from chedule_tail()), the load of current->set_child_tid causes a call to __asan_load8() to be emitted immediately prior to the __put_user_4 call, and Naresh Kamboju reports that various mmstress tests fail on KASAN-enabled builds. It's also possible to synthesize a broken case without KASAN if one uses "foo()" as the ptr argument, with foo being some "extern u64 __user *foo(void);" (though I don't know if that appears in real code). Fix it by making sure ptr gets evaluated before the assignment to __val_pu, and add a comment that __val_pu must be the last thing computed before the asm() is entered. Cc: Sean Christopherson <sean.j.christopherson@intel.com> Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> Fixes: d55564cfc222 ("x86: Make __put_user() generate an out-of-line call") Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-23Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds44-2359/+5013
Pull KVM updates from Paolo Bonzini: "For x86, there is a new alternative and (in the future) more scalable implementation of extended page tables that does not need a reverse map from guest physical addresses to host physical addresses. For now it is disabled by default because it is still lacking a few of the existing MMU's bells and whistles. However it is a very solid piece of work and it is already available for people to hammer on it. Other updates: ARM: - New page table code for both hypervisor and guest stage-2 - Introduction of a new EL2-private host context - Allow EL2 to have its own private per-CPU variables - Support of PMU event filtering - Complete rework of the Spectre mitigation PPC: - Fix for running nested guests with in-kernel IRQ chip - Fix race condition causing occasional host hard lockup - Minor cleanups and bugfixes x86: - allow trapping unknown MSRs to userspace - allow userspace to force #GP on specific MSRs - INVPCID support on AMD - nested AMD cleanup, on demand allocation of nested SVM state - hide PV MSRs and hypercalls for features not enabled in CPUID - new test for MSR_IA32_TSC writes from host and guest - cleanups: MMU, CPUID, shared MSRs - LAPIC latency optimizations ad bugfixes" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (232 commits) kvm: x86/mmu: NX largepage recovery for TDP MMU kvm: x86/mmu: Don't clear write flooding count for direct roots kvm: x86/mmu: Support MMIO in the TDP MMU kvm: x86/mmu: Support write protection for nesting in tdp MMU kvm: x86/mmu: Support disabling dirty logging for the tdp MMU kvm: x86/mmu: Support dirty logging for the TDP MMU kvm: x86/mmu: Support changed pte notifier in tdp MMU kvm: x86/mmu: Add access tracking for tdp_mmu kvm: x86/mmu: Support invalidate range MMU notifier for TDP MMU kvm: x86/mmu: Allocate struct kvm_mmu_pages for all pages in TDP MMU kvm: x86/mmu: Add TDP MMU PF handler kvm: x86/mmu: Remove disallowed_hugepage_adjust shadow_walk_iterator arg kvm: x86/mmu: Support zapping SPTEs in the TDP MMU KVM: Cache as_id in kvm_memory_slot kvm: x86/mmu: Add functions to handle changed TDP SPTEs kvm: x86/mmu: Allocate and free TDP MMU roots kvm: x86/mmu: Init / Uninit the TDP MMU kvm: x86/mmu: Introduce tdp_iter KVM: mmu: extract spte.h and spte.c KVM: mmu: Separate updating a PTE from kvm_set_pte_rmapp ...
2020-10-23Merge tag 'arch-cleanup-2020-10-22' of git://git.kernel.dk/linux-blockLinus Torvalds2-2/+2
Pull arch task_work cleanups from Jens Axboe: "Two cleanups that don't fit other categories: - Finally get the task_work_add() cleanup done properly, so we don't have random 0/1/false/true/TWA_SIGNAL confusing use cases. Updates all callers, and also fixes up the documentation for task_work_add(). - While working on some TIF related changes for 5.11, this TIF_NOTIFY_RESUME cleanup fell out of that. Remove some arch duplication for how that is handled" * tag 'arch-cleanup-2020-10-22' of git://git.kernel.dk/linux-block: task_work: cleanup notification modes tracehook: clear TIF_NOTIFY_RESUME in tracehook_notify_resume()
2020-10-23xen/events: only register debug interrupt for 2-level eventsJuergen Gross2-8/+13
xen_debug_interrupt() is specific to 2-level event handling. So don't register it with fifo event handling being active. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Link: https://lore.kernel.org/r/20201022094907.28560-4-jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2020-10-23kvm: x86/mmu: NX largepage recovery for TDP MMUBen Gardon3-4/+18
When KVM maps a largepage backed region at a lower level in order to make it executable (i.e. NX large page shattering), it reduces the TLB performance of that region. In order to avoid making this degradation permanent, KVM must periodically reclaim shattered NX largepages by zapping them and allowing them to be rebuilt in the page fault handler. With this patch, the TDP MMU does not respect KVM's rate limiting on reclaim. It traverses the entire TDP structure every time. This will be addressed in a future patch. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-21-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-23kvm: x86/mmu: Don't clear write flooding count for direct rootsBen Gardon1-1/+7
Direct roots don't have a write flooding count because the guest can't affect that paging structure. Thus there's no need to clear the write flooding count on a fast CR3 switch for direct roots. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-20-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-23kvm: x86/mmu: Support MMIO in the TDP MMUBen Gardon3-21/+72
In order to support MMIO, KVM must be able to walk the TDP paging structures to find mappings for a given GFN. Support this walk for the TDP MMU. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 v2: Thanks to Dan Carpenter and kernel test robot for finding that root was used uninitialized in get_mmio_spte. Signed-off-by: Ben Gardon <bgardon@google.com> Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Message-Id: <20201014182700.2888246-19-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-23kvm: x86/mmu: Support write protection for nesting in tdp MMUBen Gardon3-0/+57
To support nested virtualization, KVM will sometimes need to write protect pages which are part of a shadowed paging structure or are not writable in the shadowed paging structure. Add a function to write protect GFN mappings for this purpose. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-18-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-23kvm: x86/mmu: Support disabling dirty logging for the tdp MMUBen Gardon3-0/+63
Dirty logging ultimately breaks down MMU mappings to 4k granularity. When dirty logging is no longer needed, these granaular mappings represent a useless performance penalty. When dirty logging is disabled, search the paging structure for mappings that could be re-constituted into a large page mapping. Zap those mappings so that they can be faulted in again at a higher mapping level. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-17-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-23kvm: x86/mmu: Support dirty logging for the TDP MMUBen Gardon4-5/+325
Dirty logging is a key feature of the KVM MMU and must be supported by the TDP MMU. Add support for both the write protection and PML dirty logging modes. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-16-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-23kvm: x86/mmu: Support changed pte notifier in tdp MMUBen Gardon3-1/+67
In order to interoperate correctly with the rest of KVM and other Linux subsystems, the TDP MMU must correctly handle various MMU notifiers. Add a hook and handle the change_pte MMU notifier. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-15-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-23kvm: x86/mmu: Add access tracking for tdp_mmuBen Gardon3-7/+128
In order to interoperate correctly with the rest of KVM and other Linux subsystems, the TDP MMU must correctly handle various MMU notifiers. The main Linux MM uses the access tracking MMU notifiers for swap and other features. Add hooks to handle the test/flush HVA (range) family of MMU notifiers. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-14-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-23kvm: x86/mmu: Support invalidate range MMU notifier for TDP MMUBen Gardon3-6/+86
In order to interoperate correctly with the rest of KVM and other Linux subsystems, the TDP MMU must correctly handle various MMU notifiers. Add hooks to handle the invalidate range family of MMU notifiers. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-13-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>