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2020-01-24x86/asm: add iosubmit_cmds512() based on MOVDIR64B CPU instructionDave Jiang
With the introduction of MOVDIR64B instruction, there is now an instruction that can write 64 bytes of data atomically. Quoting from Intel SDM: "There is no atomicity guarantee provided for the 64-byte load operation from source address, and processor implementations may use multiple load operations to read the 64-bytes. The 64-byte direct-store issued by MOVDIR64B guarantees 64-byte write-completion atomicity. This means that the data arrives at the destination in a single undivided 64-byte write transaction." We have identified at least 3 different use cases for this instruction in the format of func(dst, src, count): 1) Clear poison / Initialize MKTME memory @dst is normal memory. @src in normal memory. Does not increment. (Copy same line to all targets) @count (to clear/init multiple lines) 2) Submit command(s) to new devices @dst is a special MMIO region for a device. Does not increment. @src is normal memory. Increments. @count usually is 1, but can be multiple. 3) Copy to iomem in big chunks @dst is iomem and increments @src in normal memory and increments @count is number of chunks to copy Add support for case #2 to support device that will accept commands via this instruction. We provide a @count in order to submit a batch of preprogrammed descriptors in virtually contiguous memory. This allows the caller to submit multiple descriptors to a device with a single submission. The special device requires the entire 64bytes descriptor to be written atomically and will accept MOVDIR64B instruction. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Acked-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/157965022175.73301.10174614665472962675.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-01-23x86/mpx: remove MPX from arch/x86Dave Hansen
From: Dave Hansen <dave.hansen@linux.intel.com> MPX is being removed from the kernel due to a lack of support in the toolchain going forward (gcc). This removes all the remaining (dead at this point) MPX handling code remaining in the tree. The only remaining code is the XSAVE support for MPX state which is currently needd for KVM to handle VMs which might use MPX. Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: x86@kernel.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
2020-01-23mm: remove arch_bprm_mm_init() hookDave Hansen
From: Dave Hansen <dave.hansen@linux.intel.com> MPX is being removed from the kernel due to a lack of support in the toolchain going forward (gcc). arch_bprm_mm_init() is used at execve() time. The only non-stub implementation is on x86 for MPX. Remove the hook entirely from all architectures and generic code. Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: x86@kernel.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-arch@vger.kernel.org Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
2020-01-22platform/x86: intel_pmc_ipc: Drop intel_pmc_gcr_read() and intel_pmc_gcr_write()Mika Westerberg
These functions are not used anywhere so drop them completely. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2020-01-22platform/x86: intel_pmc_ipc: Make intel_pmc_ipc_raw_cmd() staticMika Westerberg
This function is not called outside of intel_pmc_ipc.c so we can make it static instead. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2020-01-22platform/x86: intel_pmc_ipc: Make intel_pmc_ipc_simple_command() staticMika Westerberg
This function is not called outside of intel_pmc_ipc.c so we can make it static instead. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2020-01-22platform/x86: intel_pmc_ipc: Make intel_pmc_gcr_update() staticMika Westerberg
This function is not called outside of intel_pmc_ipc.c so we can make it static instead. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2020-01-22platform/x86: intel_scu_ipc: Drop intel_scu_ipc_raw_command()Mika Westerberg
There is no user for this function so we can drop it from the driver. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2020-01-22platform/x86: intel_scu_ipc: Drop intel_scu_ipc_io[read|write][8|16]()Mika Westerberg
There are no users for these so we can remove them. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2020-01-22platform/x86: intel_scu_ipc: Drop unused prototype intel_scu_ipc_fw_update()Mika Westerberg
There is no implementation for that anymore so drop the prototype. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2020-01-22platform/x86: intel_scu_ipc: Drop intel_scu_ipc_i2c_cntrl()Mika Westerberg
There are no existing users for this functionality so drop it from the driver completely. This also means we don't need to keep the struct intel_scu_ipc_pdata_t around anymore so remove that as well. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2020-01-21KVM: x86: Add dedicated emulator helpers for querying CPUID featuresSean Christopherson
Add feature-specific helpers for querying guest CPUID support from the emulator instead of having the emulator do a full CPUID and perform its own bit tests. The primary motivation is to eliminate the emulator's usage of bit() so that future patches can add more extensive build-time assertions on the usage of bit() without having to expose yet more code to the emulator. Note, providing a generic guest_cpuid_has() to the emulator doesn't work due to the existing built-time assertions in guest_cpuid_has(), which require the feature being checked to be a compile-time constant. No functional change intended. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-21KVM: Fix some writing mistakesMiaohe Lin
Fix some writing mistakes in the comments. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-21KVM: VMX: FIXED+PHYSICAL mode single target IPI fastpathWanpeng Li
ICR and TSCDEADLINE MSRs write cause the main MSRs write vmexits in our product observation, multicast IPIs are not as common as unicast IPI like RESCHEDULE_VECTOR and CALL_FUNCTION_SINGLE_VECTOR etc. This patch introduce a mechanism to handle certain performance-critical WRMSRs in a very early stage of KVM VMExit handler. This mechanism is specifically used for accelerating writes to x2APIC ICR that attempt to send a virtual IPI with physical destination-mode, fixed delivery-mode and single target. Which was found as one of the main causes of VMExits for Linux workloads. The reason this mechanism significantly reduce the latency of such virtual IPIs is by sending the physical IPI to the target vCPU in a very early stage of KVM VMExit handler, before host interrupts are enabled and before expensive operations such as reacquiring KVM’s SRCU lock. Latency is reduced even more when KVM is able to use APICv posted-interrupt mechanism (which allows to deliver the virtual IPI directly to target vCPU without the need to kick it to host). Testing on Xeon Skylake server: The virtual IPI latency from sender send to receiver receive reduces more than 200+ cpu cycles. Reviewed-by: Liran Alon <liran.alon@oracle.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Liran Alon <liran.alon@oracle.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-20efi/x86: Limit EFI old memory map to SGI UV machinesArd Biesheuvel
We carry a quirk in the x86 EFI code to switch back to an older method of mapping the EFI runtime services memory regions, because it was deemed risky at the time to implement a new method without providing a fallback to the old method in case problems arose. Such problems did arise, but they appear to be limited to SGI UV1 machines, and so these are the only ones for which the fallback gets enabled automatically (via a DMI quirk). The fallback can be enabled manually as well, by passing efi=old_map, but there is very little evidence that suggests that this is something that is being relied upon in the field. Given that UV1 support is not enabled by default by the distros (Ubuntu, Fedora), there is no point in carrying this fallback code all the time if there are no other users. So let's move it into the UV support code, and document that efi=old_map now requires this support code to be enabled. Note that efi=old_map has been used in the past on other SGI UV machines to work around kernel regressions in production, so we keep the option to enable it by hand, but only if the kernel was built with UV support. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200113172245.27925-8-ardb@kernel.org
2020-01-20efi/libstub/x86: Use const attribute for efi_is_64bit()Ard Biesheuvel
Reshuffle the x86 stub code a bit so that we can tag the efi_is_64bit() function with the 'const' attribute, which permits the compiler to optimize away any redundant calls. Since we have two different entry points for 32 and 64 bit firmware in the startup code, this also simplifies the C code since we'll enter it with the efi_is64 variable already set. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200113172245.27925-2-ardb@kernel.org
2020-01-17x86/hyper-v: Add "polling" bit to hv_synic_sintWei Liu
That bit is documented in TLFS 5.0c as follows: Setting the polling bit will have the effect of unmasking an interrupt source, except that an actual interrupt is not generated. Signed-off-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20191222233404.1629-1-wei.liu@kernel.org
2020-01-16x86/MCE/AMD, EDAC/mce_amd: Add new Load Store unit McaTypeYazen Ghannam
Add support for a new version of the Load Store unit bank type as indicated by its McaType value, which will be present in future SMCA systems. Add the new (HWID, MCATYPE) tuple. Reuse the same name, since this is logically the same to the user. Also, add the new error descriptions to edac_mce_amd. Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200110015651.14887-2-Yazen.Ghannam@amd.com
2020-01-14x86/vdso: Add time napespace pageDmitry Safonov
To support time namespaces in the VDSO with a minimal impact on regular non time namespace affected tasks, the namespace handling needs to be hidden in a slow path. The most obvious place is vdso_seq_begin(). If a task belongs to a time namespace then the VVAR page which contains the system wide VDSO data is replaced with a namespace specific page which has the same layout as the VVAR page. That page has vdso_data->seq set to 1 to enforce the slow path and vdso_data->clock_mode set to VCLOCK_TIMENS to enforce the time namespace handling path. The extra check in the case that vdso_data->seq is odd, e.g. a concurrent update of the VDSO data is in progress, is not really affecting regular tasks which are not part of a time namespace as the task is spin waiting for the update to finish and vdso_data->seq to become even again. If a time namespace task hits that code path, it invokes the corresponding time getter function which retrieves the real VVAR page, reads host time and then adds the offset for the requested clock which is stored in the special VVAR page. Allocate the time namespace page among VVAR pages and place vdso_data on it. Provide __arch_get_timens_vdso_data() helper for VDSO code to get the code-relative position of VVARs on that special page. Co-developed-by: Andrei Vagin <avagin@openvz.org> Signed-off-by: Andrei Vagin <avagin@openvz.org> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191112012724.250792-23-dima@arista.com
2020-01-14x86/vdso: Provide vdso_data offset on vvar_pageDmitry Safonov
VDSO support for time namespaces needs to set up a page with the same layout as VVAR. That timens page will be placed on position of VVAR page inside namespace. That page has vdso_data->seq set to 1 to enforce the slow path and vdso_data->clock_mode set to VCLOCK_TIMENS to enforce the time namespace handling path. To prepare the time namespace page the kernel needs to know the vdso_data offset. Provide arch_get_vdso_data() helper for locating vdso_data on VVAR page. Co-developed-by: Andrei Vagin <avagin@openvz.org> Signed-off-by: Andrei Vagin <avagin@openvz.org> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191112012724.250792-22-dima@arista.com
2020-01-14x86/vdso: Remove unused VDSO_HAS_32BIT_FALLBACKVincenzo Frascino
VDSO_HAS_32BIT_FALLBACK has been removed from the core since the architectures that support the generic vDSO library have been converted to support the 32 bit fallbacks. Remove unused VDSO_HAS_32BIT_FALLBACK from x86 vdso. Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20190830135902.20861-9-vincenzo.frascino@arm.com
2020-01-13perf/x86: Provide stubs of KVM helpers for non-Intel CPUsSean Christopherson
Provide stubs for perf_guest_get_msrs() and intel_pt_handle_vmx() when building without support for Intel CPUs, i.e. CPU_SUP_INTEL=n. Lack of stubs is not currently a problem as the only user, KVM_INTEL, takes a dependency on CPU_SUP_INTEL=y. Provide the stubs for all CPUs so that KVM_INTEL can be built for any CPU with compatible hardware support, e.g. Centuar and Zhaoxin CPUs. Note, the existing stub for perf_guest_get_msrs() is essentially dead code as KVM selects CONFIG_PERF_EVENTS, i.e. the only user guarantees the full implementation is built. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-19-sean.j.christopherson@intel.com
2020-01-13KVM: VMX: Use VMX_FEATURE_* flags to define VMCS control bitsSean Christopherson
Define the VMCS execution control flags (consumed by KVM) using their associated VMX_FEATURE_* to provide a strong hint that new VMX features are expected to be added to VMX_FEATURE and considered for reporting via /proc/cpuinfo. No functional change intended. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-18-sean.j.christopherson@intel.com
2020-01-13x86/cpufeatures: Add flag to track whether MSR IA32_FEAT_CTL is configuredSean Christopherson
Add a new feature flag, X86_FEATURE_MSR_IA32_FEAT_CTL, to track whether IA32_FEAT_CTL has been initialized. This will allow KVM, and any future subsystems that depend on IA32_FEAT_CTL, to rely purely on cpufeatures to query platform support, e.g. allows a future patch to remove KVM's manual IA32_FEAT_CTL MSR checks. Various features (on platforms that support IA32_FEAT_CTL) are dependent on IA32_FEAT_CTL being configured and locked, e.g. VMX and LMCE. The MSR is always configured during boot, but only if the CPU vendor is recognized by the kernel. Because CPUID doesn't incorporate the current IA32_FEAT_CTL value in its reporting of relevant features, it's possible for a feature to be reported as supported in cpufeatures but not truly enabled, e.g. if the CPU supports VMX but the kernel doesn't recognize the CPU. As a result, without the flag, KVM would see VMX as supported even if IA32_FEAT_CTL hasn't been initialized, and so would need to manually read the MSR and check the various enabling bits to avoid taking an unexpected #GP on VMXON. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-14-sean.j.christopherson@intel.com
2020-01-13x86/cpu: Detect VMX features on Intel, Centaur and Zhaoxin CPUsSean Christopherson
Add an entry in struct cpuinfo_x86 to track VMX capabilities and fill the capabilities during IA32_FEAT_CTL MSR initialization. Make the VMX capabilities dependent on IA32_FEAT_CTL and X86_FEATURE_NAMES so as to avoid unnecessary overhead on CPUs that can't possibly support VMX, or when /proc/cpuinfo is not available. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-11-sean.j.christopherson@intel.com
2020-01-13x86/vmx: Introduce VMX_FEATURES_*Sean Christopherson
Add a VMX-specific variant of X86_FEATURE_* flags, which will eventually supplant the synthetic VMX flags defined in cpufeatures word 8. Use the Intel-defined layouts for the major VMX execution controls so that their word entries can be directly populated from their respective MSRs, and so that the VMX_FEATURE_* flags can be used to define the existing bit definitions in asm/vmx.h, i.e. force developers to define a VMX_FEATURE flag when adding support for a new hardware feature. The majority of Intel's (and compatible CPU's) VMX capabilities are enumerated via MSRs and not CPUID, i.e. querying /proc/cpuinfo doesn't naturally provide any insight into the virtualization capabilities of VMX enabled CPUs. Commit e38e05a85828d ("x86: extended "flags" to show virtualization HW feature in /proc/cpuinfo") attempted to address the issue by synthesizing select VMX features into a Linux-defined word in cpufeatures. Lack of reporting of VMX capabilities via /proc/cpuinfo is problematic because there is no sane way for a user to query the capabilities of their platform, e.g. when trying to find a platform to test a feature or debug an issue that has a hardware dependency. Lack of reporting is especially problematic when the user isn't familiar with VMX, e.g. the format of the MSRs is non-standard, existence of some MSRs is reported by bits in other MSRs, several "features" from KVM's point of view are enumerated as 3+ distinct features by hardware, etc... The synthetic cpufeatures approach has several flaws: - The set of synthesized VMX flags has become extremely stale with respect to the full set of VMX features, e.g. only one new flag (EPT A/D) has been added in the the decade since the introduction of the synthetic VMX features. Failure to keep the VMX flags up to date is likely due to the lack of a mechanism that forces developers to consider whether or not a new feature is worth reporting. - The synthetic flags may incorrectly be misinterpreted as affecting kernel behavior, i.e. KVM, the kernel's sole consumer of VMX, completely ignores the synthetic flags. - New CPU vendors that support VMX have duplicated the hideous code that propagates VMX features from MSRs to cpufeatures. Bringing the synthetic VMX flags up to date would exacerbate the copy+paste trainwreck. Define separate VMX_FEATURE flags to set the stage for enumerating VMX capabilities outside of the cpu_has() framework, and for adding functional usage of VMX_FEATURE_* to help ensure the features reported via /proc/cpuinfo is up to date with respect to kernel recognition of VMX capabilities. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-10-sean.j.christopherson@intel.com
2020-01-13x86/msr-index: Clean up bit defines for IA32_FEATURE_CONTROL MSRSean Christopherson
As pointed out by Boris, the defines for bits in IA32_FEATURE_CONTROL are quite a mouthful, especially the VMX bits which must differentiate between enabling VMX inside and outside SMX (TXT) operation. Rename the MSR and its bit defines to abbreviate FEATURE_CONTROL as FEAT_CTL to make them a little friendlier on the eyes. Arguably, the MSR itself should keep the full IA32_FEATURE_CONTROL name to match Intel's SDM, but a future patch will add a dedicated Kconfig, file and functions for the MSR. Using the full name for those assets is rather unwieldy, so bite the bullet and use IA32_FEAT_CTL so that its nomenclature is consistent throughout the kernel. Opportunistically, fix a few other annoyances with the defines: - Relocate the bit defines so that they immediately follow the MSR define, e.g. aren't mistaken as belonging to MISC_FEATURE_CONTROL. - Add whitespace around the block of feature control defines to make it clear they're all related. - Use BIT() instead of manually encoding the bit shift. - Use "VMX" instead of "VMXON" to match the SDM. - Append "_ENABLED" to the LMCE (Local Machine Check Exception) bit to be consistent with the kernel's verbiage used for all other feature control bits. Note, the SDM refers to the LMCE bit as LMCE_ON, likely to differentiate it from IA32_MCG_EXT_CTL.LMCE_EN. Ignore the (literal) one-off usage of _ON, the SDM is simply "wrong". Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-2-sean.j.christopherson@intel.com
2020-01-13x86/mce: Take action on UCNA/Deferred errors againJan H. Schönherr
Commit fa92c5869426 ("x86, mce: Support memory error recovery for both UCNA and Deferred error in machine_check_poll") added handling of UCNA and Deferred errors by adding them to the ring for SRAO errors. Later, commit fd4cf79fcc4b ("x86/mce: Remove the MCE ring for Action Optional errors") switched storage from the SRAO ring to the unified pool that is still in use today. In order to only act on the intended errors, a filter for MCE_AO_SEVERITY is used -- effectively removing handling of UCNA/Deferred errors again. Extend the severity filter to include UCNA/Deferred errors again. Also, generalize the naming of the notifier from SRAO to UC to capture the extended scope. Note, that this change may cause a message like the following to appear, as the same address may be reported as SRAO and as UCNA: Memory failure: 0x5fe3284: already hardware poisoned Technically, this is a return to previous behavior. Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Tony Luck <tony.luck@intel.com> Link: https://lkml.kernel.org/r/20200103150722.20313-2-jschoenh@amazon.de
2020-01-11x86/nmi: Remove irq_work from the long duration NMI handlerChangbin Du
First, printk() is NMI-context safe now since the safe printk() has been implemented and it already has an irq_work to make NMI-context safe. Second, this NMI irq_work actually does not work if a NMI handler causes panic by watchdog timeout. It has no chance to run in such case, while the safe printk() will flush its per-cpu buffers before panicking. While at it, repurpose the irq_work callback into a function which concentrates the NMI duration checking and makes the code easier to follow. [ bp: Massage. ] Signed-off-by: Changbin Du <changbin.du@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200111125427.15662-1-changbin.du@gmail.com
2020-01-10efi: Allow disabling PCI busmastering on bridges during bootMatthew Garrett
Add an option to disable the busmaster bit in the control register on all PCI bridges before calling ExitBootServices() and passing control to the runtime kernel. System firmware may configure the IOMMU to prevent malicious PCI devices from being able to attack the OS via DMA. However, since firmware can't guarantee that the OS is IOMMU-aware, it will tear down IOMMU configuration when ExitBootServices() is called. This leaves a window between where a hostile device could still cause damage before Linux configures the IOMMU again. If CONFIG_EFI_DISABLE_PCI_DMA is enabled or "efi=disable_early_pci_dma" is passed on the command line, the EFI stub will clear the busmaster bit on all PCI bridges before ExitBootServices() is called. This will prevent any malicious PCI devices from being able to perform DMA until the kernel reenables busmastering after configuring the IOMMU. This option may cause failures with some poorly behaved hardware and should not be enabled without testing. The kernel commandline options "efi=disable_early_pci_dma" or "efi=no_disable_early_pci_dma" may be used to override the default. Note that PCI devices downstream from PCI bridges are disconnected from their drivers first, using the UEFI driver model API, so that DMA can be disabled safely at the bridge level. [ardb: disconnect PCI I/O handles first, as suggested by Arvind] Co-developed-by: Matthew Garrett <mjg59@google.com> Signed-off-by: Matthew Garrett <mjg59@google.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Matthew Garrett <matthewgarrett@google.com> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20200103113953.9571-18-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-01-10efi/x86: Allow translating 64-bit arguments for mixed mode callsArvind Sankar
Introduce the ability to define macros to perform argument translation for the calls that need it, and define them for the boot services that we currently use. When calling 32-bit firmware methods in mixed mode, all output parameters that are 32-bit according to the firmware, but 64-bit in the kernel (ie OUT UINTN * or OUT VOID **) must be initialized in the kernel, or the upper 32 bits may contain garbage. Define macros that zero out the upper 32 bits of the output before invoking the firmware method. When a 32-bit EFI call takes 64-bit arguments, the mixed-mode call must push the two 32-bit halves as separate arguments onto the stack. This can be achieved by splitting the argument into its two halves when calling the assembler thunk. Define a macro to do this for the free_pages boot service. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Matthew Garrett <mjg59@google.com> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20200103113953.9571-17-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-01-10efi/x86: Check number of arguments to variadic functionsArvind Sankar
On x86 we need to thunk through assembler stubs to call the EFI services for mixed mode, and for runtime services in 64-bit mode. The assembler stubs have limits on how many arguments it handles. Introduce a few macros to check that we do not try to pass too many arguments to the stubs. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Matthew Garrett <mjg59@google.com> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20200103113953.9571-16-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-01-10efi/x86: Simplify mixed mode call wrapperArd Biesheuvel
Calling 32-bit EFI runtime services from a 64-bit OS involves switching back to the flat mapping with a stack carved out of memory that is 32-bit addressable. There is no need to actually execute the 64-bit part of this routine from the flat mapping as well, as long as the entry and return address fit in 32 bits. There is also no need to preserve part of the calling context in global variables: we can simply push the old stack pointer value to the new stack, and keep the return address from the code32 section in EBX. While at it, move the conditional check whether to invoke the mixed mode version of SetVirtualAddressMap() into the 64-bit implementation of the wrapper routine. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Matthew Garrett <mjg59@google.com> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20200103113953.9571-11-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-01-10efi/x86: Simplify i386 efi_call_phys() firmware call wrapperArd Biesheuvel
The variadic efi_call_phys() wrapper that exists on i386 was originally created to call into any EFI firmware runtime service, but in practice, we only use it once, to call SetVirtualAddressMap() during early boot. The flexibility provided by the variadic nature also makes it type unsafe, and makes the assembler code more complicated than needed, since it has to deal with an unknown number of arguments living on the stack. So clean this up, by renaming the helper to efi_call_svam(), and dropping the unneeded complexity. Let's also drop the reference to the efi_phys struct and grab the address from the EFI system table directly. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Matthew Garrett <mjg59@google.com> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20200103113953.9571-9-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-01-10efi/x86: Split SetVirtualAddresMap() wrappers into 32 and 64 bit versionsArd Biesheuvel
Split the phys_efi_set_virtual_address_map() routine into 32 and 64 bit versions, so we can simplify them individually in subsequent patches. There is very little overlap between the logic anyway, and this has already been factored out in prolog/epilog routines which are completely different between 32 bit and 64 bit. So let's take it one step further, and get rid of the overlap completely. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Matthew Garrett <mjg59@google.com> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20200103113953.9571-8-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-01-10efi/x86: Avoid redundant cast of EFI firmware service pointerArd Biesheuvel
All EFI firmware call prototypes have been annotated as __efiapi, permitting us to attach attributes regarding the calling convention by overriding __efiapi to an architecture specific value. On 32-bit x86, EFI firmware calls use the plain calling convention where all arguments are passed via the stack, and cleaned up by the caller. Let's add this to the __efiapi definition so we no longer need to cast the function pointers before invoking them. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Matthew Garrett <mjg59@google.com> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20200103113953.9571-6-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-01-10efi/x86: Re-disable RT services for 32-bit kernels running on 64-bit EFIArd Biesheuvel
Commit a8147dba75b1 ("efi/x86: Rename efi_is_native() to efi_is_mixed()") renamed and refactored efi_is_native() into efi_is_mixed(), but failed to take into account that these are not diametrical opposites. Mixed mode is a construct that permits 64-bit kernels to boot on 32-bit firmware, but there is another non-native combination which is supported, i.e., 32-bit kernels booting on 64-bit firmware, but only for boot and not for runtime services. Also, mixed mode can be disabled in Kconfig, in which case the 64-bit kernel can still be booted from 32-bit firmware, but without access to runtime services. Due to this oversight, efi_runtime_supported() now incorrectly returns true for such configurations, resulting in crashes at boot. So fix this by making efi_runtime_supported() aware of this. As a side effect, some efi_thunk_xxx() stubs have become obsolete, so remove them as well. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Matthew Garrett <mjg59@google.com> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20200103113953.9571-4-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-01-10Merge branch 'x86/mm' into efi/core, to pick up dependenciesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-01-10platform/x86: intel_telemetry_pltdrv: use devm_platform_ioremap_resource()Andy Shevchenko
Use devm_platform_ioremap_resource() to simplify the code a bit. While here, drop initialized but unused ssram_base_addr and ssram_size members. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2020-01-09crypto: remove CRYPTO_TFM_RES_BAD_KEY_LENEric Biggers
The CRYPTO_TFM_RES_BAD_KEY_LEN flag was apparently meant as a way to make the ->setkey() functions provide more information about errors. However, no one actually checks for this flag, which makes it pointless. Also, many algorithms fail to set this flag when given a bad length key. Reviewing just the generic implementations, this is the case for aes-fixed-time, cbcmac, echainiv, nhpoly1305, pcrypt, rfc3686, rfc4309, rfc7539, rfc7539esp, salsa20, seqiv, and xcbc. But there are probably many more in arch/*/crypto/ and drivers/crypto/. Some algorithms can even set this flag when the key is the correct length. For example, authenc and authencesn set it when the key payload is malformed in any way (not just a bad length), the atmel-sha and ccree drivers can set it if a memory allocation fails, and the chelsio driver sets it for bad auth tag lengths, not just bad key lengths. So even if someone actually wanted to start checking this flag (which seems unlikely, since it's been unused for a long time), there would be a lot of work needed to get it working correctly. But it would probably be much better to go back to the drawing board and just define different return values, like -EINVAL if the key is invalid for the algorithm vs. -EKEYREJECTED if the key was rejected by a policy like "no weak keys". That would be much simpler, less error-prone, and easier to test. So just remove this flag. Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Horia Geantă <horia.geanta@nxp.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-01-08x86: Remove force_iret()Brian Gerst
force_iret() was originally intended to prevent the return to user mode with the SYSRET or SYSEXIT instructions, in cases where the register state could have been changed to be incompatible with those instructions. The entry code has been significantly reworked since then, and register state is validated before SYSRET or SYSEXIT are used. force_iret() no longer serves its original purpose and can be eliminated. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Oleg Nesterov <oleg@redhat.com> Link: https://lkml.kernel.org/r/20191219115812.102620-1-brgerst@gmail.com
2020-01-08KVM: x86: Use gpa_t for cr2/gpa to fix TDP support on 32-bit KVMSean Christopherson
Convert a plethora of parameters and variables in the MMU and page fault flows from type gva_t to gpa_t to properly handle TDP on 32-bit KVM. Thanks to PSE and PAE paging, 32-bit kernels can access 64-bit physical addresses. When TDP is enabled, the fault address is a guest physical address and thus can be a 64-bit value, even when both KVM and its guest are using 32-bit virtual addressing, e.g. VMX's VMCS.GUEST_PHYSICAL is a 64-bit field, not a natural width field. Using a gva_t for the fault address means KVM will incorrectly drop the upper 32-bits of the GPA. Ditto for gva_to_gpa() when it is used to translate L2 GPAs to L1 GPAs. Opportunistically rename variables and parameters to better reflect the dual address modes, e.g. use "cr2_or_gpa" for fault addresses and plain "addr" instead of "vaddr" when the address may be either a GVA or an L2 GPA. Similarly, use "gpa" in the nonpaging_page_fault() flows to avoid a confusing "gpa_t gva" declaration; this also sets the stage for a future patch to combing nonpaging_page_fault() and tdp_page_fault() with minimal churn. Sprinkle in a few comments to document flows where an address is known to be a GVA and thus can be safely truncated to a 32-bit value. Add WARNs in kvm_handle_page_fault() and FNAME(gva_to_gpa_nested)() to help document such cases and detect bugs. Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08KVM: VMX: Fix the spelling of CPU_BASED_USE_TSC_OFFSETTINGXiaoyao Li
The mis-spelling is found by checkpatch.pl, so fix them. Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08KVM: VMX: Rename NMI_PENDING to NMI_WINDOWXiaoyao Li
Rename the NMI-window exiting related definitions to match the latest Intel SDM. No functional changes. Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08KVM: VMX: Rename INTERRUPT_PENDING to INTERRUPT_WINDOWXiaoyao Li
Rename interrupt-windown exiting related definitions to match the latest Intel SDM. No functional changes. Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08KVM: X86: Use APIC_DEST_* macros properly in kvm_lapic_irq.dest_modePeter Xu
We were using either APIC_DEST_PHYSICAL|APIC_DEST_LOGICAL or 0|1 to fill in kvm_lapic_irq.dest_mode. It's fine only because in most cases when we check against dest_mode it's against APIC_DEST_PHYSICAL (which equals to 0). However, that's not consistent. We'll have problem when we want to start checking against APIC_DEST_LOGICAL, which does not equals to 1. This patch firstly introduces kvm_lapic_irq_dest_mode() helper to take any boolean of destination mode and return the APIC_DEST_* macro. Then, it replaces the 0|1 settings of irq.dest_mode with the helper. Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08x86/cpufeatures: Add support for fast short REP; MOVSBTony Luck
>From the Intel Optimization Reference Manual: 3.7.6.1 Fast Short REP MOVSB Beginning with processors based on Ice Lake Client microarchitecture, REP MOVSB performance of short operations is enhanced. The enhancement applies to string lengths between 1 and 128 bytes long. Support for fast-short REP MOVSB is enumerated by the CPUID feature flag: CPUID [EAX=7H, ECX=0H).EDX.FAST_SHORT_REP_MOVSB[bit 4] = 1. There is no change in the REP STOS performance. Add an X86_FEATURE_FSRM flag for this. memmove() avoids REP MOVSB for short (< 32 byte) copies. Check FSRM and use REP MOVSB for short copies on systems that support it. [ bp: Massage and add comment. ] Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191216214254.26492-1-tony.luck@intel.com
2020-01-03compat: provide compat_ptr() on all architecturesArnd Bergmann
In order to avoid needless #ifdef CONFIG_COMPAT checks, move the compat_ptr() definition to linux/compat.h where it can be seen by any file regardless of the architecture. Only s390 needs a special definition, this can use the self-#define trick we have elsewhere. Reviewed-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2020-01-02x86/nospec: Remove unused RSB_FILL_LOOPSAnthony Steinhauser
It was never really used, see 117cc7a908c8 ("x86/retpoline: Fill return stack buffer on vmexit") [ bp: Massage. ] Signed-off-by: Anthony Steinhauser <asteinhauser@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20191226204512.24524-1-asteinhauser@google.com
2019-12-31x86/dumpstack: Introduce die_addr() for die() with #GP fault addressJann Horn
Split __die() into __die_header() and __die_body(). This allows inserting extra information below the header line that initiates the bug report. Introduce a new function die_addr() that behaves like die(), but is for faults only and uses __die_header() and __die_body() so that a future commit can print extra information after the header line. [ bp: Comment the KASAN-specific usage of gp_addr. ] Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: kasan-dev@googlegroups.com Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20191218231150.12139-3-jannh@google.com