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2021-07-01kernel.h: split out panic and oops helpersAndy Shevchenko
kernel.h is being used as a dump for all kinds of stuff for a long time. Here is the attempt to start cleaning it up by splitting out panic and oops helpers. There are several purposes of doing this: - dropping dependency in bug.h - dropping a loop by moving out panic_notifier.h - unload kernel.h from something which has its own domain At the same time convert users tree-wide to use new headers, although for the time being include new header back to kernel.h to avoid twisted indirected includes for existing users. [akpm@linux-foundation.org: thread_info.h needs limits.h] [andriy.shevchenko@linux.intel.com: ia64 fix] Link: https://lkml.kernel.org/r/20210520130557.55277-1-andriy.shevchenko@linux.intel.com Link: https://lkml.kernel.org/r/20210511074137.33666-1-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Co-developed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Corey Minyard <cminyard@mvista.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Wei Liu <wei.liu@kernel.org> Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Sebastian Reichel <sre@kernel.org> Acked-by: Luis Chamberlain <mcgrof@kernel.org> Acked-by: Stephen Boyd <sboyd@kernel.org> Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Acked-by: Helge Deller <deller@gmx.de> # parisc Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-27Merge tag 'printk-for-5.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk updates from Petr Mladek: - Stop synchronizing kernel log buffer readers by logbuf_lock. As a result, the access to the buffer is fully lockless now. Note that printk() itself still uses locks because it tries to flush the messages to the console immediately. Also the per-CPU temporary buffers are still there because they prevent infinite recursion and serialize backtraces from NMI. All this is going to change in the future. - kmsg_dump API rework and cleanup as a side effect of the logbuf_lock removal. - Make bstr_printf() aware that %pf and %pF formats could deference the given pointer. - Show also page flags by %pGp format. - Clarify the documentation for plain pointer printing. - Do not show no_hash_pointers warning multiple times. - Update Senozhatsky email address. - Some clean up. * tag 'printk-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (24 commits) lib/vsprintf.c: remove leftover 'f' and 'F' cases from bstr_printf() printk: clarify the documentation for plain pointer printing kernel/printk.c: Fixed mundane typos printk: rename vprintk_func to vprintk vsprintf: dump full information of page flags in pGp mm, slub: don't combine pr_err with INFO mm, slub: use pGp to print page flags MAINTAINERS: update Senozhatsky email address lib/vsprintf: do not show no_hash_pointers message multiple times printk: console: remove unnecessary safe buffer usage printk: kmsg_dump: remove _nolock() variants printk: remove logbuf_lock printk: introduce a kmsg_dump iterator printk: kmsg_dumper: remove @active field printk: add syslog_lock printk: use atomic64_t for devkmsg_user.seq printk: use seqcount_latch for clear_seq printk: introduce CONSOLE_LOG_MAX printk: consolidate kmsg_dump_get_buffer/syslog_print_all code printk: refactor kmsg_dump_get_buffer() ...
2021-04-18Drivers: hv: vmbus: Drivers: hv: vmbus: Introduce ↵Andrea Parri (Microsoft)
CHANNELMSG_MODIFYCHANNEL_RESPONSE Introduce the CHANNELMSG_MODIFYCHANNEL_RESPONSE message type, and code to receive and process such a message. Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210416143449.16185-3-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08Drivers: hv: vmbus: Move handling of VMbus interruptsMichael Kelley
VMbus interrupts are most naturally modelled as per-cpu IRQs. But because x86/x64 doesn't have per-cpu IRQs, the core VMbus interrupt handling machinery is done in code under arch/x86 and Linux IRQs are not used. Adding support for ARM64 means adding equivalent code using per-cpu IRQs under arch/arm64. A better model is to treat per-cpu IRQs as the normal path (which it is for modern architectures), and the x86/x64 path as the exception. Do this by incorporating standard Linux per-cpu IRQ allocation into the main VMbus driver, and bypassing it in the x86/x64 exception case. For x86/x64, special case code is retained under arch/x86, but no VMbus interrupt handling code is needed under arch/arm64. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/1614721102-2241-7-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08Drivers: hv: vmbus: Move hyperv_report_panic_msg to arch neutral codeMichael Kelley
With the new Hyper-V MSR set function, hyperv_report_panic_msg() can be architecture neutral, so move it out from under arch/x86 and merge into hv_kmsg_dump(). This move also avoids needing a separate implementation under arch/arm64. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/1614721102-2241-5-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08Drivers: hv: Redo Hyper-V synthetic MSR get/set functionsMichael Kelley
Current code defines a separate get and set macro for each Hyper-V synthetic MSR used by the VMbus driver. Furthermore, the get macro can't be converted to a standard function because the second argument is modified in place, which is somewhat bad form. Redo this by providing a single get and a single set function that take a parameter specifying the MSR to be operated on. Fixup usage of the get function. Calling locations are no more complex than before, but the code under arch/x86 and the upcoming code under arch/arm64 is significantly simplified. Also standardize the names of Hyper-V synthetic MSRs that are architecture neutral. But keep the old x86-specific names as aliases that can be removed later when all references (particularly in KVM code) have been cleaned up in a separate patch series. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/1614721102-2241-4-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08printk: introduce a kmsg_dump iteratorJohn Ogness
Rather than storing the iterator information in the registered kmsg_dumper structure, create a separate iterator structure. The kmsg_dump_iter structure can reside on the stack of the caller, thus allowing lockless use of the kmsg_dump functions. Update code that accesses the kernel logs using the kmsg_dumper structure to use the new kmsg_dump_iter structure. For kmsg_dumpers, this also means adding a call to kmsg_dump_rewind() to initialize the iterator. All this is in preparation for removal of @logbuf_lock. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> # pstore Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210303101528.29901-13-john.ogness@linutronix.de
2021-02-11Drivers: hv: vmbus: skip VMBus initialization if Linux is rootWei Liu
There is no VMBus and the other infrastructures initialized in hv_acpi_init when Linux is running as the root partition. Signed-off-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210203150435.27941-4-wei.liu@kernel.org
2021-02-11Drivers: hv: vmbus: Add /sys/bus/vmbus/hibernationDexuan Cui
When a Linux VM runs on Hyper-V, if the host toolstack doesn't support hibernation for the VM (this happens on old Hyper-V hosts like Windows Server 2016, or new Hyper-V hosts if the admin or user doesn't declare the hibernation intent for the VM), the VM is discouraged from trying hibernation (because the host doesn't guarantee that the VM's virtual hardware configuration will remain exactly the same across hibernation), i.e. the VM should not try to set up the swap partition/file for hibernation, etc. x86 Hyper-V uses the presence of the virtual ACPI S4 state as the indication of the host toolstack support for a VM. Currently there is no easy and reliable way for the userspace to detect the presence of the state (see https://lkml.org/lkml/2020/12/11/1097). Add /sys/bus/vmbus/hibernation for this purpose. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210107014552.14234-1-decui@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-05Drivers: hv: vmbus: Copy the hv_message in vmbus_on_msg_dpc()Andrea Parri (Microsoft)
Since the message is in memory shared with the host, an erroneous or a malicious Hyper-V could 'corrupt' the message while vmbus_on_msg_dpc() or individual message handlers are executing. To prevent it, copy the message into private memory. Reported-by: Juan Vazquez <juvazq@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201209070827.29335-4-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-05Drivers: hv: vmbus: Reduce number of references to message in vmbus_on_msg_dpc()Andrea Parri (Microsoft)
Simplify the function by removing various references to the hv_message 'msg', introduce local variables 'msgtype' and 'payload_size'. Suggested-by: Juan Vazquez <juvazq@microsoft.com> Suggested-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201209070827.29335-3-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-01-05x86/hyperv: Fix kexec panic/hang issuesDexuan Cui
Currently the kexec kernel can panic or hang due to 2 causes: 1) hv_cpu_die() is not called upon kexec, so the hypervisor corrupts the old VP Assist Pages when the kexec kernel runs. The same issue is fixed for hibernation in commit 421f090c819d ("x86/hyperv: Suspend/resume the VP assist page for hibernation"). Now fix it for kexec. 2) hyperv_cleanup() is called too early. In the kexec path, the other CPUs are stopped in hv_machine_shutdown() -> native_machine_shutdown(), so between hv_kexec_handler() and native_machine_shutdown(), the other CPUs can still try to access the hypercall page and cause panic. The workaround "hv_hypercall_pg = NULL;" in hyperv_cleanup() is unreliabe. Move hyperv_cleanup() to a better place. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201222065541.24312-1-decui@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-12-02drivers: hv: vmbus: Fix checkpatch SPLIT_STRINGMatheus Castello
Checkpatch emits WARNING: quoted string split across lines. To keep the code clean and with the 80 column length indentation the check and registration code for kmsg_dump_register has been transferred to a new function hv_kmsg_dump_register. Signed-off-by: Matheus Castello <matheus@castello.eng.br> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201125032926.17002-1-matheus@castello.eng.br Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-17drivers: hv: vmbus: Fix call msleep using < 20msMatheus Castello
Fixed checkpatch warning: MSLEEP: msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.rst Signed-off-by: Matheus Castello <matheus@castello.eng.br> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201115195734.8338-7-matheus@castello.eng.br Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-17drivers: hv: vmbus: Fix checkpatch LINE_SPACINGMatheus Castello
Fixed checkpatch warning: Missing a blank line after declarations checkpatch(LINE_SPACING) Signed-off-by: Matheus Castello <matheus@castello.eng.br> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201115195734.8338-4-matheus@castello.eng.br Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-17drivers: hv: vmbus: Replace symbolic permissions by octal permissionsMatheus Castello
This fixed the below checkpatch issue: WARNING: Symbolic permissions 'S_IRUGO' are not preferred. Consider using octal permissions '0444'. Signed-off-by: Matheus Castello <matheus@castello.eng.br> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201115195734.8338-3-matheus@castello.eng.br Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-17drivers: hv: Fix hyperv_record_panic_msg path on commentMatheus Castello
Fix the kernel parameter path in the comment, in the documentation the parameter is correct but if someone who is studying the code and see this first can get confused and try to access the wrong path/parameter Signed-off-by: Matheus Castello <matheus@castello.eng.br> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201115195734.8338-2-matheus@castello.eng.br Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-10-15Merge tag 'hyperv-next-signed' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull another Hyper-V update from Wei Liu: "One patch from Michael to get VMbus interrupt from ACPI DSDT" * tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: Drivers: hv: vmbus: Add parsing of VMbus interrupt in ACPI DSDT
2020-10-14Drivers: hv: vmbus: Add parsing of VMbus interrupt in ACPI DSDTMichael Kelley
On ARM64, Hyper-V now specifies the interrupt to be used by VMbus in the ACPI DSDT. This information is not used on x86 because the interrupt vector must be hardcoded. But update the generic VMbus driver to do the parsing and pass the information to the architecture specific code that sets up the Linux IRQ. Update consumers of the interrupt to get it from an architecture specific function. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1597434304-40631-1-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-10-14Merge tag 'hyperv-next-signed' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull Hyper-V updates from Wei Liu: - a series from Boqun Feng to support page size larger than 4K - a few miscellaneous clean-ups * tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: hv: clocksource: Add notrace attribute to read_hv_sched_clock_*() functions x86/hyperv: Remove aliases with X64 in their name PCI: hv: Document missing hv_pci_protocol_negotiation() parameter scsi: storvsc: Support PAGE_SIZE larger than 4K Driver: hv: util: Use VMBUS_RING_SIZE() for ringbuffer sizes HID: hyperv: Use VMBUS_RING_SIZE() for ringbuffer sizes Input: hyperv-keyboard: Use VMBUS_RING_SIZE() for ringbuffer sizes hv_netvsc: Use HV_HYP_PAGE_SIZE for Hyper-V communication hv: hyperv.h: Introduce some hvpfn helper functions Drivers: hv: vmbus: Move virt_to_hvpfn() to hyperv header Drivers: hv: Use HV_HYP_PAGE in hv_synic_enable_regs() Drivers: hv: vmbus: Introduce types of GPADL Drivers: hv: vmbus: Move __vmbus_open() Drivers: hv: vmbus: Always use HV_HYP_PAGE_SIZE for gpadl drivers: hv: remove cast from hyperv_die_event
2020-09-15Merge tag 'hyperv-fixes-signed' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv fixes from Wei Liu: "Two patches from Michael and Dexuan to fix vmbus hanging issues" * tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: Drivers: hv: vmbus: Add timeout to vmbus_wait_for_unload Drivers: hv: vmbus: hibernation: do not hang forever in vmbus_bus_resume()
2020-09-09Drivers: hv: vmbus: hibernation: do not hang forever in vmbus_bus_resume()Dexuan Cui
After we Stop and later Start a VM that uses Accelerated Networking (NIC SR-IOV), currently the VF vmbus device's Instance GUID can change, so after vmbus_bus_resume() -> vmbus_request_offers(), vmbus_onoffer() can not find the original vmbus channel of the VF, and hence we can't complete() vmbus_connection.ready_for_resume_event in check_ready_for_resume_event(), and the VM hangs in vmbus_bus_resume() forever. Fix the issue by adding a timeout, so the resuming can still succeed, and the saved state is not lost, and according to my test, the user can disable Accelerated Networking and then will be able to SSH into the VM for further recovery. Also prevent the VM in question from suspending again. The host will be fixed so in future the Instance GUID will stay the same across hibernation. Fixes: d8bd2d442bb2 ("Drivers: hv: vmbus: Resume after fixing up old primary channels") Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200905025555.45614-1-decui@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-08-19drivers: hv: remove cast from hyperv_die_eventOlaf Hering
No need to cast a void pointer. Signed-off-by: Olaf Hering <olaf@aepfle.de> Link: https://lore.kernel.org/r/20200819090510.28995-1-olaf@aepfle.de Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-08-14Merge tag 'hyperv-fixes-signed' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyper-v fixes from Wei Liu: - fix oops reporting on Hyper-V - make objtool happy * tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: x86/hyperv: Make hv_setup_sched_clock inline Drivers: hv: vmbus: Only notify Hyper-V for die events that are oops
2020-08-07Drivers: hv: vmbus: Only notify Hyper-V for die events that are oopsMichael Kelley
Hyper-V currently may be notified of a panic for any die event. But this results in false panic notifications for various user space traps that are die events. Fix this by ignoring die events that aren't oops. Fixes: 510f7aef65bb ("Drivers: hv: vmbus: prefer 'die' notification chain to 'panic'") Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Link: https://lore.kernel.org/r/1596730935-11564-1-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-08-06Merge tag 'hyperv-next-signed' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv updates from Wei Liu: - A patch series from Andrea to improve vmbus code - Two clean-up patches from Alexander and Randy * tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: hyperv: hyperv.h: drop a duplicated word tools: hv: change http to https in hv_kvp_daemon.c Drivers: hv: vmbus: Remove the lock field from the vmbus_channel struct scsi: storvsc: Introduce the per-storvsc_device spinlock Drivers: hv: vmbus: Remove unnecessary channel->lock critical sections (sc_list updaters) Drivers: hv: vmbus: Use channel_mutex in channel_vp_mapping_show() Drivers: hv: vmbus: Remove unnecessary channel->lock critical sections (sc_list readers) Drivers: hv: vmbus: Replace cpumask_test_cpu(, cpu_online_mask) with cpu_online() Drivers: hv: vmbus: Remove the numa_node field from the vmbus_channel struct Drivers: hv: vmbus: Remove the target_vp field from the vmbus_channel struct
2020-06-29Drivers: hv: Change flag to write log level in panic msg to falseJoseph Salisbury
When the kernel panics, one page of kmsg data may be collected and sent to Hyper-V to aid in diagnosing the failure. The collected kmsg data typically contains 50 to 100 lines, each of which has a log level prefix that isn't very useful from a diagnostic standpoint. So tell kmsg_dump_get_buffer() to not include the log level, enabling more information that *is* useful to fit in the page. Requesting in stable kernels, since many kernels running in production are stable releases. Cc: stable@vger.kernel.org Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1593210497-114310-1-git-send-email-joseph.salisbury@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-19Drivers: hv: vmbus: Use channel_mutex in channel_vp_mapping_show()Andrea Parri (Microsoft)
The primitive currently uses channel->lock to protect the loop over sc_list w.r.t. list additions/deletions but it doesn't protect the target_cpu(s) loads w.r.t. a concurrent target_cpu_store(): while the data races on target_cpu are hardly of any concern here, replace the channel->lock critical section with a channel_mutex critical section and extend the latter to include the loads of target_cpu; this same pattern is also used in hv_synic_cleanup(). Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200617164642.37393-6-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-19Drivers: hv: vmbus: Remove unnecessary channel->lock critical sections ↵Andrea Parri (Microsoft)
(sc_list readers) Additions/deletions to/from sc_list (as well as modifications of target_cpu(s)) are protected by channel_mutex, which hv_synic_cleanup() and vmbus_bus_suspend() own for the duration of the channel->lock critical section in question. Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200617164642.37393-5-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-19Drivers: hv: vmbus: Replace cpumask_test_cpu(, cpu_online_mask) with ↵Andrea Parri (Microsoft)
cpu_online() A slight improvement in readability, and this does also remove one memory access when NR_CPUS == 1! ;-) Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200617164642.37393-4-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-19Drivers: hv: vmbus: Remove the numa_node field from the vmbus_channel structAndrea Parri (Microsoft)
The field is read only in numa_node_show() and it is already stored twice (after a call to cpu_to_node()) in target_cpu_store() and init_vp_index(); there is no need to "cache" its value in the channel data structure. Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200617164642.37393-3-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-19Drivers: hv: vmbus: Remove the target_vp field from the vmbus_channel structAndrea Parri (Microsoft)
The field is read only in __vmbus_open() and it is already stored twice (after a call to hv_cpu_number_to_vp_number()) in target_cpu_store() and init_vp_index(); there is no need to "cache" its value in the channel data structure. Suggested-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200617164642.37393-2-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-03Merge tag 'hyperv-next-signed' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyper-v updates from Wei Liu: - a series from Andrea to support channel reassignment - a series from Vitaly to clean up Vmbus message handling - a series from Michael to clean up and augment hyperv-tlfs.h - patches from Andy to clean up GUID usage in Hyper-V code - a few other misc patches * tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (29 commits) Drivers: hv: vmbus: Resolve more races involving init_vp_index() Drivers: hv: vmbus: Resolve race between init_vp_index() and CPU hotplug vmbus: Replace zero-length array with flexible-array Driver: hv: vmbus: drop a no long applicable comment hyper-v: Switch to use UUID types directly hyper-v: Replace open-coded variant of %*phN specifier hyper-v: Supply GUID pointer to printf() like functions hyper-v: Use UUID API for exporting the GUID (part 2) asm-generic/hyperv: Add definitions for Get/SetVpRegister hypercalls x86/hyperv: Split hyperv-tlfs.h into arch dependent and independent files x86/hyperv: Remove HV_PROCESSOR_POWER_STATE #defines KVM: x86: hyperv: Remove duplicate definitions of Reference TSC Page drivers: hv: remove redundant assignment to pointer primary_channel scsi: storvsc: Re-init stor_chns when a channel interrupt is re-assigned Drivers: hv: vmbus: Introduce the CHANNELMSG_MODIFYCHANNEL message type Drivers: hv: vmbus: Synchronize init_vp_index() vs. CPU hotplug Drivers: hv: vmbus: Remove the unused HV_LOCALIZED channel affinity logic PCI: hv: Prepare hv_compose_msi_msg() for the VMBus-channel-interrupt-to-vCPU reassignment functionality Drivers: hv: vmbus: Use a spin lock for synchronizing channel scheduling vs. channel removal hv_utils: Always execute the fcopy and vss callbacks in a tasklet ...
2020-05-23Drivers: hv: vmbus: Resolve more races involving init_vp_index()Andrea Parri (Microsoft)
init_vp_index() uses the (per-node) hv_numa_map[] masks to record the CPUs allocated for channel interrupts at a given time, and distribute the performance-critical channels across the available CPUs: in part., the mask of "candidate" target CPUs in a given NUMA node, for a newly offered channel, is determined by XOR-ing the node's CPU mask and the node's hv_numa_map. This operation/mechanism assumes that no offline CPUs is set in the hv_numa_map mask, an assumption that does not hold since such mask is currently not updated when a channel is removed or assigned to a different CPU. To address the issues described above, this adds hooks in the channel removal path (hv_process_channel_removal()) and in target_cpu_store() in order to clear, resp. to update, the hv_numa_map[] masks as needed. This also adds a (missed) update of the masks in init_vp_index() (cf., e.g., the memory-allocation failure path in this function). Like in the case of init_vp_index(), such hooks require to determine if the given channel is performance critical. init_vp_index() does this by parsing the channel's offer, it can not rely on the device data structure (device_obj) to retrieve such information because the device data structure has not been allocated/linked with the channel by the time that init_vp_index() executes. A similar situation may hold in hv_is_alloced_cpu() (defined below); the adopted approach is to "cache" the device type of the channel, as computed by parsing the channel's offer, in the channel structure itself. Fixes: 7527810573436f ("Drivers: hv: vmbus: Introduce the CHANNELMSG_MODIFYCHANNEL message type") Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200522171901.204127-3-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-05-20Driver: hv: vmbus: drop a no long applicable commentWei Liu
None of the things mentioned in the comment is initialized in hv_init. They've been moved elsewhere. Signed-off-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20200506160806.118965-1-wei.liu@kernel.org Reviewed-by: Michael Kelley <mikelley@microsoft.com>
2020-05-20hyper-v: Replace open-coded variant of %*phN specifierAndy Shevchenko
printf() like functions in the kernel have extensions, such as %*phN to dump small pieces of memory as hex values. Replace print_alias_name() with the direct use of %*phN. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20200423134505.78221-3-andriy.shevchenko@linux.intel.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-05-20hyper-v: Supply GUID pointer to printf() like functionsAndy Shevchenko
Drop dereference when printing the GUID with printf() like functions. This allows to hide the uuid_t internals. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20200423134505.78221-2-andriy.shevchenko@linux.intel.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-05-20scsi: storvsc: Re-init stor_chns when a channel interrupt is re-assignedAndrea Parri (Microsoft)
For each storvsc_device, storvsc keeps track of the channel target CPUs associated to the device (alloced_cpus) and it uses this information to fill a "cache" (stor_chns) mapping CPU->channel according to a certain heuristic. Update the alloced_cpus mask and the stor_chns array when a channel of the storvsc device is re-assigned to a different CPU. Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Cc: "James E.J. Bottomley" <jejb@linux.ibm.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: <linux-scsi@vger.kernel.org> Link: https://lore.kernel.org/r/20200406001514.19876-12-parri.andrea@gmail.com Reviewed-by; Long Li <longli@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> [ wei: fix a small issue reported by kbuild test robot <lkp@intel.com> ] Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: vmbus: Introduce the CHANNELMSG_MODIFYCHANNEL message typeAndrea Parri (Microsoft)
VMBus version 4.1 and later support the CHANNELMSG_MODIFYCHANNEL(22) message type which can be used to request Hyper-V to change the vCPU that a channel will interrupt. Introduce the CHANNELMSG_MODIFYCHANNEL message type, and define the vmbus_send_modifychannel() function to send CHANNELMSG_MODIFYCHANNEL requests to the host via a hypercall. The function is then used to define a sysfs "store" operation, which allows to change the (v)CPU the channel will interrupt by using the sysfs interface. The feature can be used for load balancing or other purposes. One interesting catch here is that Hyper-V can *not* currently ACK CHANNELMSG_MODIFYCHANNEL messages with the promise that (after the ACK is sent) the channel won't send any more interrupts to the "old" CPU. The peculiarity of the CHANNELMSG_MODIFYCHANNEL messages is problematic if the user want to take a CPU offline, since we don't want to take a CPU offline (and, potentially, "lose" channel interrupts on such CPU) if the host is still processing a CHANNELMSG_MODIFYCHANNEL message associated to that CPU. It is worth mentioning, however, that we have been unable to observe the above mentioned "race": in all our tests, CHANNELMSG_MODIFYCHANNEL requests appeared *as if* they were processed synchronously by the host. Suggested-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200406001514.19876-11-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> [ wei: fix conflict in channel_mgmt.c ] Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: vmbus: Use a spin lock for synchronizing channel scheduling vs. ↵Andrea Parri (Microsoft)
channel removal Since vmbus_chan_sched() dereferences the ring buffer pointer, we have to make sure that the ring buffer data structures don't get freed while such dereferencing is happening. Current code does this by sending an IPI to the CPU that is allowed to access that ring buffer from interrupt level, cf., vmbus_reset_channel_cb(). But with the new functionality to allow changing the CPU that a channel will interrupt, we can't be sure what CPU will be running the vmbus_chan_sched() function for a particular channel, so the current IPI mechanism is infeasible. Instead synchronize vmbus_chan_sched() and vmbus_reset_channel_cb() by using the (newly introduced) per-channel spin lock "sched_lock". Move the test for onchannel_callback being NULL before the "switch" control statement in vmbus_chan_sched(), in order to not access the ring buffer if the vmbus_reset_channel_cb() has been completed on the channel. Suggested-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200406001514.19876-7-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: vmbus: Replace the per-CPU channel lists with a global array of ↵Andrea Parri (Microsoft)
channels When Hyper-V sends an interrupt to the guest, the guest has to figure out which channel the interrupt is associated with. Hyper-V sets a bit in a memory page that is shared with the guest, indicating a particular "relid" that the interrupt is associated with. The current Linux code then uses a set of per-CPU linked lists to map a given "relid" to a pointer to a channel structure. This design introduces a synchronization problem if the CPU that Hyper-V will interrupt for a certain channel is changed. If the interrupt comes on the "old CPU" and the channel was already moved to the per-CPU list of the "new CPU", then the relid -> channel mapping will fail and the interrupt is dropped. Similarly, if the interrupt comes on the new CPU but the channel was not moved to the per-CPU list of the new CPU, then the mapping will fail and the interrupt is dropped. Relids are integers ranging from 0 to 2047. The mapping from relids to channel structures can be done by setting up an array with 2048 entries, each entry being a pointer to a channel structure (hence total size ~16K bytes, which is not a problem). The array is global, so there are no per-CPU linked lists to update. The array can be searched and updated by loading from/storing to the array at the specified index. With no per-CPU data structures, the above mentioned synchronization problem is avoided and the relid2channel() function gets simpler. Suggested-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200406001514.19876-4-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: vmbus: Don't bind the offer&rescind works to a specific CPUAndrea Parri (Microsoft)
The offer and rescind works are currently scheduled on the so called "connect CPU". However, this is not really needed: we can synchronize the works by relying on the usage of the offer_in_progress counter and of the channel_mutex mutex. This synchronization is already in place. So, remove this unnecessary "bind to the connect CPU" constraint and update the inline comments accordingly. Suggested-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20200406001514.19876-3-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: vmbus: Always handle the VMBus messages on CPU0Andrea Parri (Microsoft)
A Linux guest have to pick a "connect CPU" to communicate with the Hyper-V host. This CPU can not be taken offline because Hyper-V does not provide a way to change that CPU assignment. Current code sets the connect CPU to whatever CPU ends up running the function vmbus_negotiate_version(), and this will generate problems if that CPU is taken offine. Establish CPU0 as the connect CPU, and add logics to prevents the connect CPU from being taken offline. We could pick some other CPU, and we could pick that "other CPU" dynamically if there was a reason to do so at some point in the future. But for now, #defining the connect CPU to 0 is the most straightforward and least complex solution. While on this, add inline comments explaining "why" offer and rescind messages should not be handled by a same serialized work queue. Suggested-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Link: https://lore.kernel.org/r/20200406001514.19876-2-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: check VMBus messages lengthsVitaly Kuznetsov
VMBus message handlers (channel_message_table) receive a pointer to 'struct vmbus_channel_message_header' and cast it to a structure of their choice, which is sometimes longer than the header. We, however, don't check that the message is long enough so in case hypervisor screws up we'll be accessing memory beyond what was allocated for temporary buffer. Previously, we used to always allocate and copy 256 bytes from message page to temporary buffer but this is hardly better: in case the message is shorter than we expect we'll be trying to consume garbage as some real data and no memory guarding technique will be able to identify an issue. Introduce 'min_payload_len' to 'struct vmbus_channel_message_table_entry' and check against it in vmbus_on_msg_dpc(). Note, we can't require the exact length as new hypervisor versions may add extra fields to messages, we only check that the message is not shorter than we expect. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200406104326.45361-1-vkuznets@redhat.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: make sure that 'struct vmbus_channel_message_header' compiles ↵Vitaly Kuznetsov
correctly Strictly speaking, compiler is free to use something different from 'u32' for 'enum vmbus_channel_message_type' (e.g. char) but it doesn't happen in real life, just add a BUILD_BUG_ON() guardian. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200406104316.45303-1-vkuznets@redhat.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: avoid passing opaque pointer to vmbus_onmessage()Vitaly Kuznetsov
vmbus_onmessage() doesn't need the header of the message, it only uses it to get to the payload, we can pass the pointer to the payload directly. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200406104154.45010-4-vkuznets@redhat.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: allocate the exact needed memory for messagesVitaly Kuznetsov
When we need to pass a buffer with Hyper-V message we don't need to always allocate 256 bytes for the message: the real message length is known from the header. Change 'struct onmessage_work_context' to make it possible to not over-allocate. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200406104154.45010-3-vkuznets@redhat.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23Drivers: hv: copy from message page only what's neededVitaly Kuznetsov
Hyper-V Interrupt Message Page (SIMP) has 16 256-byte slots for messages. Each message comes with a header (16 bytes) which specifies the payload length (up to 240 bytes). vmbus_on_msg_dpc(), however, doesn't look at the real message length and copies the whole slot to a temporary buffer before passing it to message handlers. This is potentially dangerous as hypervisor doesn't have to clean the whole slot when putting a new message there and a message handler can get access to some data which belongs to a previous message. Note, this is not currently a problem because all message handlers are in-kernel but eventually we may e.g. get this exported to userspace. Note also, that this is not a performance critical path: messages (unlike events) represent rare events so it doesn't really matter (from performance point of view) if we copy too much. Fix the issue by taking into account the real message length. The temporary buffer allocated by vmbus_on_msg_dpc() remains fixed size for now. Also, check that the supplied payload length is valid (<= 240 bytes). Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200406104154.45010-2-vkuznets@redhat.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-14Drivers: hv: vmbus: Fix Suspend-to-Idle for Generation-2 VMDexuan Cui
Before the hibernation patchset (e.g. f53335e3289f), in a Generation-2 Linux VM on Hyper-V, the user can run "echo freeze > /sys/power/state" to freeze the system, i.e. Suspend-to-Idle. The user can press the keyboard or move the mouse to wake up the VM. With the hibernation patchset, Linux VM on Hyper-V can hibernate to disk, but Suspend-to-Idle is broken: when the synthetic keyboard/mouse are suspended, there is no way to wake up the VM. Fix the issue by not suspending and resuming the vmbus devices upon Suspend-to-Idle. Fixes: f53335e3289f ("Drivers: hv: vmbus: Suspend/resume the vmbus itself for hibernation") Cc: stable@vger.kernel.org Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Link: https://lore.kernel.org/r/1586663435-36243-1-git-send-email-decui@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-11x86/Hyper-V: Report crash data in die() when panic_on_oops is setTianyu Lan
When oops happens with panic_on_oops unset, the oops thread is killed by die() and system continues to run. In such case, guest should not report crash register data to host since system still runs. Check panic_on_oops and return directly in hyperv_report_panic() when the function is called in the die() and panic_on_oops is unset. Fix it. Fixes: 7ed4325a44ea ("Drivers: hv: vmbus: Make panic reporting to be more useful") Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200406155331.2105-7-Tianyu.Lan@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>