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2024-11-12LoongArch: Fix AP booting issue in VM modeBibo Mao
Native IPI is used for AP booting, because it is the booting interface between OS and BIOS firmware. The paravirt IPI is only used inside OS, and native IPI is necessary to boot AP. When booting AP, we write the kernel entry address in the HW mailbox of AP and send IPI interrupt to it. AP executes idle instruction and waits for interrupts or SW events, then clears IPI interrupt and jumps to the kernel entry from HW mailbox. Between writing HW mailbox and sending IPI, AP can be woken up by SW events and jumps to the kernel entry, so ACTION_BOOT_CPU IPI interrupt will keep pending during AP booting. And native IPI interrupt handler needs be registered so that it can clear pending native IPI, else there will be endless interrupts during AP booting stage. Here native IPI interrupt is initialized even if paravirt IPI is used. Cc: stable@vger.kernel.org Fixes: 74c16b2e2b0c ("LoongArch: KVM: Add PV IPI support on guest side") Signed-off-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-09-17Merge tag 'irq-core-2024-09-16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq updates from Thomas Gleixner: "Core: - Remove a global lock in the affinity setting code The lock protects a cpumask for intermediate results and the lock causes a bottleneck on simultaneous start of multiple virtual machines. Replace the lock and the static cpumask with a per CPU cpumask which is nicely serialized by raw spinlock held when executing this code. - Provide support for giving a suffix to interrupt domain names. That's required to support devices with subfunctions so that the domain names are distinct even if they originate from the same device node. - The usual set of cleanups and enhancements all over the place Drivers: - Support for longarch AVEC interrupt chip - Refurbishment of the Armada driver so it can be extended for new variants. - The usual set of cleanups and enhancements all over the place" * tag 'irq-core-2024-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (73 commits) genirq: Use cpumask_intersects() genirq/cpuhotplug: Use cpumask_intersects() irqchip/apple-aic: Only access system registers on SoCs which provide them irqchip/apple-aic: Add a new "Global fast IPIs only" feature level irqchip/apple-aic: Skip unnecessary enabling of use_fast_ipi dt-bindings: apple,aic: Document A7-A11 compatibles irqdomain: Use IS_ERR_OR_NULL() in irq_domain_trim_hierarchy() genirq/msi: Use kmemdup_array() instead of kmemdup() genirq/proc: Change the return value for set affinity permission error genirq/proc: Use irq_move_pending() in show_irq_affinity() genirq/proc: Correctly set file permissions for affinity control files genirq: Get rid of global lock in irq_do_set_affinity() genirq: Fix typo in struct comment irqchip/loongarch-avec: Add AVEC irqchip support irqchip/loongson-pch-msi: Prepare get_pch_msi_handle() for AVECINTC irqchip/loongson-eiointc: Rename CPUHP_AP_IRQ_LOONGARCH_STARTING LoongArch: Architectural preparation for AVEC irqchip LoongArch: Move irqchip function prototypes to irq-loongson.h irqchip/loongson-pch-msi: Switch to MSI parent domains softirq: Remove unused 'action' parameter from action callback ...
2024-09-12LoongArch: KVM: Implement function kvm_para_has_feature()Bibo Mao
Implement function kvm_para_has_feature() to detect supported paravirt features. It can be used by device driver to detect and enable paravirt features, such as the EIOINTC irqchip driver is able to detect feature KVM_FEATURE_VIRT_EXTIOI and do some optimization. Signed-off-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-09-12LoongArch: KVM: Enable paravirt feature control from VMMBibo Mao
Export kernel paravirt features to user space, so that VMM can control each single paravirt feature. By default paravirt features will be the same with kvm supported features if VMM does not set it. Also a new feature KVM_FEATURE_VIRT_EXTIOI is added which can be set from user space. This feature indicates that the virt EIOINTC can route interrupts to 256 vCPUs, rather than 4 vCPUs like with real HW. Signed-off-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-09-11LoongArch: Revert qspinlock to test-and-set simple lock on VMBibo Mao
Similar with x86, when VM is detected, revert to a simple test-and-set lock to avoid the horrors of queue preemption. Tested on 3C5000 Dual-way machine with 32 cores and 2 numa nodes, test case is kcbench on kernel mainline 6.10, the detailed command is "kcbench --src /root/src/linux" Performance on host machine kernel compile time performance impact Original 150.29 seconds With patch 150.19 seconds almost no impact Performance on virtual machine: 1. 1 VM with 32 vCPUs and 2 numa node, numa node pinned kernel compile time performance impact Original 170.87 seconds With patch 171.73 seconds almost no impact 2. 2 VMs, each VM with 32 vCPUs and 2 numa node, numa node pinned kernel compile time performance impact Original 2362.04 seconds With patch 354.73 seconds +565% Signed-off-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-08-23irqchip/loongarch-avec: Add AVEC irqchip supportTianyang Zhang
Introduce the advanced extended interrupt controllers (AVECINTC). This feature will allow each core to have 256 independent interrupt vectors and MSI interrupts can be independently routed to any vector on any CPU. The whole topology of irqchips in LoongArch machines looks like this if AVECINTC is supported: +-----+ +-----------------------+ +-------+ | IPI | --> | CPUINTC | <-- | Timer | +-----+ +-----------------------+ +-------+ ^ ^ ^ | | | +---------+ +----------+ +---------+ +-------+ | EIOINTC | | AVECINTC | | LIOINTC | <-- | UARTs | +---------+ +----------+ +---------+ +-------+ ^ ^ | | +---------+ +---------+ | PCH-PIC | | PCH-MSI | +---------+ +---------+ ^ ^ ^ | | | +---------+ +---------+ +---------+ | Devices | | PCH-LPC | | Devices | +---------+ +---------+ +---------+ ^ | +---------+ | Devices | +---------+ Co-developed-by: Jianmin Lv <lvjianmin@loongson.cn> Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn> Co-developed-by: Liupu Wang <wangliupu@loongson.cn> Signed-off-by: Liupu Wang <wangliupu@loongson.cn> Co-developed-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Tianyang Zhang <zhangtianyang@loongson.cn> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20240823104337.25577-2-zhangtianyang@loongson.cn
2024-07-22Merge tag 'loongarch-6.11' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson Pull LoongArch updates from Huacai Chen: - Define __ARCH_WANT_NEW_STAT in unistd.h - Always enumerate MADT and setup logical-physical CPU mapping - Add irq_work support via self IPIs - Add RANDOMIZE_KSTACK_OFFSET support - Add ARCH_HAS_PTE_DEVMAP support - Add ARCH_HAS_DEBUG_VM_PGTABLE support - Add writecombine support for DMW-based ioremap() - Add architectural preparation for CPUFreq - Add ACPI standard hardware register based S3 support - Add support for relocating the kernel with RELR relocation - Some bug fixes and other small changes * tag 'loongarch-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson: LoongArch: Make the users of larch_insn_gen_break() constant LoongArch: Check TIF_LOAD_WATCH to enable user space watchpoint LoongArch: Use rustc option -Zdirect-access-external-data LoongArch: Add support for relocating the kernel with RELR relocation LoongArch: Remove a redundant checking in relocator LoongArch: Use correct API to map cmdline in relocate_kernel() LoongArch: Automatically disable KASLR for hibernation LoongArch: Add ACPI standard hardware register based S3 support LoongArch: Add architectural preparation for CPUFreq LoongArch: Add writecombine support for DMW-based ioremap() LoongArch: Add ARCH_HAS_DEBUG_VM_PGTABLE support LoongArch: Add ARCH_HAS_PTE_DEVMAP support LoongArch: Add RANDOMIZE_KSTACK_OFFSET support LoongArch: Add irq_work support via self IPIs LoongArch: Always enumerate MADT and setup logical-physical CPU mapping LoongArch: Define __ARCH_WANT_NEW_STAT in unistd.h
2024-07-20LoongArch: Add irq_work support via self IPIsHuacai Chen
Add irq_work support for LoongArch via self IPIs. This make it possible to run works in hardware interrupt context, which is a prerequisite for NOHZ_FULL. Implement: - arch_irq_work_raise() - arch_irq_work_has_interrupt() Reviewed-by: Guo Ren <guoren@kernel.org> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-07-09LoongArch: KVM: Add PV steal time support in guest sideBibo Mao
Per-cpu struct kvm_steal_time is added here, its size is 64 bytes and also defined as 64 bytes, so that the whole structure is in one physical page. When a VCPU is online, function pv_enable_steal_time() is called. This function will pass guest physical address of struct kvm_steal_time and tells hypervisor to enable steal time. When a vcpu is offline, physical address is set as 0 and tells hypervisor to disable steal time. Here is an output of vmstat on guest when there is workload on both host and guest. It shows steal time stat information. procs -----------memory---------- -----io---- -system-- ------cpu----- r b swpd free inact active bi bo in cs us sy id wa st 15 1 0 7583616 184112 72208 20 0 162 52 31 6 43 0 20 17 0 0 7583616 184704 72192 0 0 6318 6885 5 60 8 5 22 16 0 0 7583616 185392 72144 0 0 1766 1081 0 49 0 1 50 16 0 0 7583616 184816 72304 0 0 6300 6166 4 62 12 2 20 18 0 0 7583632 184480 72240 0 0 2814 1754 2 58 4 1 35 Signed-off-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-05-06LoongArch: KVM: Add PV IPI support on guest sideBibo Mao
PARAVIRT config option and PV IPI is added for the guest side, function pv_ipi_init() is used to add IPI sending and IPI receiving hooks. This function firstly checks whether system runs in VM mode, and if kernel runs in VM mode, it will call function kvm_para_available() to detect the current hypervirsor type (now only KVM type detection is supported). The paravirt functions can work only if current hypervisor type is KVM, since there is only KVM supported on LoongArch now. PV IPI uses virtual IPI sender and virtual IPI receiver functions. With virtual IPI sender, IPI message is stored in memory rather than emulated HW. IPI multicast is also supported, and 128 vcpus can received IPIs at the same time like X86 KVM method. Hypercall method is used for IPI sending. With virtual IPI receiver, HW SWI0 is used rather than real IPI HW. Since VCPU has separate HW SWI0 like HW timer, there is no trap in IPI interrupt acknowledge. Since IPI message is stored in memory, there is no trap in getting IPI message. Signed-off-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>