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2021-10-01KVM: x86: SVM: don't set VMLOAD/VMSAVE intercepts on vCPU resetPaolo Bonzini1-27/+34
Commit adc2a23734ac ("KVM: nSVM: improve SYSENTER emulation on AMD"), made init_vmcb set vmload/vmsave intercepts unconditionally, and relied on svm_vcpu_after_set_cpuid to clear them when possible. However init_vmcb is also called when the vCPU is reset, and it is not followed by another call to svm_vcpu_after_set_cpuid because the CPUID is already set. This mistake makes the VMSAVE/VMLOAD intercept to be set when it is not needed, and harms performance of the nested guest. Extract the relevant parts of svm_vcpu_after_set_cpuid so that they can be called again on reset. Fixes: adc2a23734ac ("KVM: nSVM: improve SYSENTER emulation on AMD") Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30x86/kprobes: Fixup return address in generic trampoline handlerMasami Hiramatsu1-2/+16
In x86, the fake return address on the stack saved by __kretprobe_trampoline() will be replaced with the real return address after returning from trampoline_handler(). Before fixing the return address, the real return address can be found in the 'current->kretprobe_instances'. However, since there is a window between updating the 'current->kretprobe_instances' and fixing the address on the stack, if an interrupt happens at that timing and the interrupt handler does stacktrace, it may fail to unwind because it can not get the correct return address from 'current->kretprobe_instances'. This will eliminate that window by fixing the return address right before updating 'current->kretprobe_instances'. Link: https://lkml.kernel.org/r/163163057094.489837.9044470370440745866.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30x86/unwind: Recover kretprobe trampoline entryMasami Hiramatsu4-8/+42
Since the kretprobe replaces the function return address with the kretprobe_trampoline on the stack, x86 unwinders can not continue the stack unwinding at that point, or record kretprobe_trampoline instead of correct return address. To fix this issue, find the correct return address from task's kretprobe_instances as like as function-graph tracer does. With this fix, the unwinder can correctly unwind the stack from kretprobe event on x86, as below. <...>-135 [003] ...1 6.722338: r_full_proxy_read_0: (vfs_read+0xab/0x1a0 <- full_proxy_read) <...>-135 [003] ...1 6.722377: <stack trace> => kretprobe_trace_func+0x209/0x2f0 => kretprobe_dispatcher+0x4a/0x70 => __kretprobe_trampoline_handler+0xca/0x150 => trampoline_handler+0x44/0x70 => kretprobe_trampoline+0x2a/0x50 => vfs_read+0xab/0x1a0 => ksys_read+0x5f/0xe0 => do_syscall_64+0x33/0x40 => entry_SYSCALL_64_after_hwframe+0x44/0xae Link: https://lkml.kernel.org/r/163163055130.489837.5161749078833497255.stgit@devnote2 Reported-by: Daniel Xu <dxu@dxuuu.xyz> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com> Tested-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30x86/kprobes: Push a fake return address at kretprobe_trampolineMasami Hiramatsu1-9/+25
Change __kretprobe_trampoline() to push the address of the __kretprobe_trampoline() as a fake return address at the bottom of the stack frame. This fake return address will be replaced with the correct return address in the trampoline_handler(). With this change, the ORC unwinder can check whether the return address is modified by kretprobes or not. Link: https://lkml.kernel.org/r/163163054185.489837.14338744048957727386.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com> Tested-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30arm: kprobes: Make space for instruction pointer on stackMasami Hiramatsu1-0/+2
Since arm's __kretprobe_trampoline() saves partial 'pt_regs' on the stack, 'regs->ARM_pc' (instruction pointer) is not accessible from the kretprobe handler. This means if instruction_pointer_set() is used from kretprobe handler, it will break the data on the stack. Make space for instruction pointer (ARM_pc) on the stack in the __kretprobe_trampoline() for fixing this problem. Link: https://lkml.kernel.org/r/163163052262.489837.10327621053231461255.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30ia64: Add instruction_pointer_set() APIMasami Hiramatsu1-0/+5
Add instruction_pointer_set() API for ia64. Link: https://lkml.kernel.org/r/163163051195.489837.1039597819838213481.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30ARC: Add instruction_pointer_set() APIMasami Hiramatsu1-0/+5
Add instruction_pointer_set() API for arc. Link: https://lkml.kernel.org/r/163163050148.489837.15187799269793560256.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30x86/kprobes: Add UNWIND_HINT_FUNC on kretprobe_trampoline()Josh Poimboeuf2-2/+16
Add UNWIND_HINT_FUNC on __kretprobe_trampoline() code so that ORC information is generated on the __kretprobe_trampoline() correctly. Also, this uses STACK_FRAME_NON_STANDARD_FP(), CONFIG_FRAME_POINTER- -specific version of STACK_FRAME_NON_STANDARD(). Link: https://lkml.kernel.org/r/163163049242.489837.11970969750993364293.stgit@devnote2 Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30kprobes: treewide: Make it harder to refer kretprobe_trampoline directlyMasami Hiramatsu27-72/+73
Since now there is kretprobe_trampoline_addr() for referring the address of kretprobe trampoline code, we don't need to access kretprobe_trampoline directly. Make it harder to refer by renaming it to __kretprobe_trampoline(). Link: https://lkml.kernel.org/r/163163045446.489837.14510577516938803097.stgit@devnote2 Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30kprobes: treewide: Remove trampoline_address from kretprobe_trampoline_handler()Masami Hiramatsu14-20/+15
The __kretprobe_trampoline_handler() callback, called from low level arch kprobes methods, has the 'trampoline_address' parameter, which is entirely superfluous as it basically just replicates: dereference_kernel_function_descriptor(kretprobe_trampoline) In fact we had bugs in arch code where it wasn't replicated correctly. So remove this superfluous parameter and use kretprobe_trampoline_addr() instead. Link: https://lkml.kernel.org/r/163163044546.489837.13505751885476015002.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30kprobes: treewide: Replace arch_deref_entry_point() with dereference_symbol_descriptor()Masami Hiramatsu2-16/+0
~15 years ago kprobes grew the 'arch_deref_entry_point()' __weak function: 3d7e33825d87: ("jprobes: make jprobes a little safer for users") But this is just open-coded dereference_symbol_descriptor() in essence, and its obscure nature was causing bugs. Just use the real thing and remove arch_deref_entry_point(). Link: https://lkml.kernel.org/r/163163043630.489837.7924988885652708696.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30ia64: kprobes: Fix to pass correct trampoline address to the handlerMasami Hiramatsu1-4/+5
The following commit: Commit e792ff804f49 ("ia64: kprobes: Use generic kretprobe trampoline handler") Passed the wrong trampoline address to __kretprobe_trampoline_handler(): it passes the descriptor address instead of function entry address. Pass the right parameter. Also use correct symbol dereference function to get the function address from 'kretprobe_trampoline' - an IA64 special. Link: https://lkml.kernel.org/r/163163042696.489837.12551102356265354730.stgit@devnote2 Fixes: e792ff804f49 ("ia64: kprobes: Use generic kretprobe trampoline handler") Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: X86 ML <x86@kernel.org> Cc: Daniel Xu <dxu@dxuuu.xyz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Abhishek Sagar <sagar.abhishek@gmail.com> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com> Cc: Paul McKenney <paulmck@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30kprobes: treewide: Use 'kprobe_opcode_t *' for the code address in get_optimized_kprobe()Masami Hiramatsu3-9/+10
Since get_optimized_kprobe() is only used inside kprobes, it doesn't need to use 'unsigned long' type for 'addr' parameter. Make it use 'kprobe_opcode_t *' for the 'addr' parameter and subsequent call of arch_within_optimized_kprobe() also should use 'kprobe_opcode_t *'. Note that MAX_OPTIMIZED_LENGTH and RELATIVEJUMP_SIZE are defined by byte-size, but the size of 'kprobe_opcode_t' depends on the architecture. Therefore, we must be careful when calculating addresses using those macros. Link: https://lkml.kernel.org/r/163163040680.489837.12133032364499833736.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30kprobes: treewide: Cleanup the error messages for kprobesMasami Hiramatsu6-20/+25
This clean up the error/notification messages in kprobes related code. Basically this defines 'pr_fmt()' macros for each files and update the messages which describes - what happened, - what is the kernel going to do or not do, - is the kernel fine, - what can the user do about it. Also, if the message is not needed (e.g. the function returns unique error code, or other error message is already shown.) remove it, and replace the message with WARN_*() macros if suitable. Link: https://lkml.kernel.org/r/163163036568.489837.14085396178727185469.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30csky: ftrace: Drop duplicate implementation of arch_check_ftrace_location()Punit Agrawal1-7/+0
The csky specific arch_check_ftrace_location() shadows a weak implementation of the function in core code that offers the same functionality but with additional error checking. Drop the architecture specific function as a step towards further cleanup in core code. Link: https://lkml.kernel.org/r/163163034617.489837.7789033031868135258.stgit@devnote2 Signed-off-by: Punit Agrawal <punitagrawal@gmail.com> Acked-by: Guo Ren <guoren@kernel.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski78-658/+756
drivers/net/phy/bcm7xxx.c d88fd1b546ff ("net: phy: bcm7xxx: Fixed indirect MMD operations") f68d08c437f9 ("net: phy: bcm7xxx: Add EPHY entry for 72165") net/sched/sch_api.c b193e15ac69d ("net: prevent user from passing illegal stab size") 69508d43334e ("net_sched: Use struct_size() and flex_array_size() helpers") Both cases trivial - adjacent code additions. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-09-30Merge tag 'net-5.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds2-32/+91
Pull networking fixes from Jakub Kicinski: "Networking fixes, including fixes from mac80211, netfilter and bpf. Current release - regressions: - bpf, cgroup: assign cgroup in cgroup_sk_alloc when called from interrupt - mdio: revert mechanical patches which broke handling of optional resources - dev_addr_list: prevent address duplication Previous releases - regressions: - sctp: break out if skb_header_pointer returns NULL in sctp_rcv_ootb (NULL deref) - Revert "mac80211: do not use low data rates for data frames with no ack flag", fixing broadcast transmissions - mac80211: fix use-after-free in CCMP/GCMP RX - netfilter: include zone id in tuple hash again, minimize collisions - netfilter: nf_tables: unlink table before deleting it (race -> UAF) - netfilter: log: work around missing softdep backend module - mptcp: don't return sockets in foreign netns - sched: flower: protect fl_walk() with rcu (race -> UAF) - ixgbe: fix NULL pointer dereference in ixgbe_xdp_setup - smsc95xx: fix stalled rx after link change - enetc: fix the incorrect clearing of IF_MODE bits - ipv4: fix rtnexthop len when RTA_FLOW is present - dsa: mv88e6xxx: 6161: use correct MAX MTU config method for this SKU - e100: fix length calculation & buffer overrun in ethtool::get_regs Previous releases - always broken: - mac80211: fix using stale frag_tail skb pointer in A-MSDU tx - mac80211: drop frames from invalid MAC address in ad-hoc mode - af_unix: fix races in sk_peer_pid and sk_peer_cred accesses (race -> UAF) - bpf, x86: Fix bpf mapping of atomic fetch implementation - bpf: handle return value of BPF_PROG_TYPE_STRUCT_OPS prog - netfilter: ip6_tables: zero-initialize fragment offset - mhi: fix error path in mhi_net_newlink - af_unix: return errno instead of NULL in unix_create1() when over the fs.file-max limit Misc: - bpf: exempt CAP_BPF from checks against bpf_jit_limit - netfilter: conntrack: make max chain length random, prevent guessing buckets by attackers - netfilter: nf_nat_masquerade: make async masq_inet6_event handling generic, defer conntrack walk to work queue (prevent hogging RTNL lock)" * tag 'net-5.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (77 commits) af_unix: fix races in sk_peer_pid and sk_peer_cred accesses net: stmmac: fix EEE init issue when paired with EEE capable PHYs net: dev_addr_list: handle first address in __hw_addr_add_ex net: sched: flower: protect fl_walk() with rcu net: introduce and use lock_sock_fast_nested() net: phy: bcm7xxx: Fixed indirect MMD operations net: hns3: disable firmware compatible features when uninstall PF net: hns3: fix always enable rx vlan filter problem after selftest net: hns3: PF enable promisc for VF when mac table is overflow net: hns3: fix show wrong state when add existing uc mac address net: hns3: fix mixed flag HCLGE_FLAG_MQPRIO_ENABLE and HCLGE_FLAG_DCB_ENABLE net: hns3: don't rollback when destroy mqprio fail net: hns3: remove tc enable checking net: hns3: do not allow call hns3_nic_net_open repeatedly ixgbe: Fix NULL pointer dereference in ixgbe_xdp_setup net: bridge: mcast: Associate the seqcount with its protecting lock. net: mdio-ipq4019: Fix the error for an optional regs resource net: hns3: fix hclge_dbg_dump_tm_pg() stack usage net: mdio: mscc-miim: Fix the mdio controller af_unix: Return errno instead of NULL in unix_create1(). ...
2021-09-30riscv: rely on core code to keep thread_info::cpu updatedArd Biesheuvel3-7/+0
Now that the core code switched back to using thread_info::cpu to keep a task's CPU number, we no longer need to keep it in sync explicitly. So just drop the code that does this. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com> Acked-by: Mark Rutland <mark.rutland@arm.com>
2021-09-30powerpc: smp: remove hack to obtain offset of task_struct::cpuArd Biesheuvel3-29/+1
Instead of relying on awful hacks to obtain the offset of the cpu field in struct task_struct, move it back into struct thread_info, which does not create the same level of circular dependency hell when trying to include the header file that defines it. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au>
2021-09-30sched: move CPU field back into thread_info if THREAD_INFO_IN_TASK=yArd Biesheuvel4-4/+3
THREAD_INFO_IN_TASK moved the CPU field out of thread_info, but this causes some issues on architectures that define raw_smp_processor_id() in terms of this field, due to the fact that #include'ing linux/sched.h to get at struct task_struct is problematic in terms of circular dependencies. Given that thread_info and task_struct are the same data structure anyway when THREAD_INFO_IN_TASK=y, let's move it back so that having access to the type definition of struct thread_info is sufficient to reference the CPU number of the current task. Note that this requires THREAD_INFO_IN_TASK's definition of the task_thread_info() helper to be updated, as task_cpu() takes a pointer-to-const, whereas task_thread_info() (which is used to generate lvalues as well), needs a non-const pointer. So make it a macro instead. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au>
2021-09-30powerpc: add CPU field to struct thread_infoArd Biesheuvel1-0/+3
The CPU field will be moved back into thread_info even when THREAD_INFO_IN_TASK is enabled, so add it back to powerpc's definition of struct thread_info. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au>
2021-09-30s390: add CPU field to struct thread_infoArd Biesheuvel1-0/+1
The CPU field will be moved back into thread_info even when THREAD_INFO_IN_TASK is enabled, so add it back to s390's definition of struct thread_info. Note that s390 always has CONFIG_SMP=y so there is no point in guarding the CPU field with an #ifdef. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com>
2021-09-30x86: add CPU field to struct thread_infoArd Biesheuvel1-0/+3
The CPU field will be moved back into thread_info even when THREAD_INFO_IN_TASK is enabled, so add it back to x86's definition of struct thread_info. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Borislav Petkov <bp@suse.de> Acked-by: Mark Rutland <mark.rutland@arm.com>
2021-09-30arm64: add CPU field to struct thread_infoArd Biesheuvel2-0/+2
The CPU field will be moved back into thread_info even when THREAD_INFO_IN_TASK is enabled, so add it back to arm64's definition of struct thread_info. Note that arm64 always has CONFIG_SMP=y so there is no point in guarding the CPU field with an #ifdef. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com>
2021-09-30ARM: dts: exynos: use spaces instead of tabs around '='Krzysztof Kozlowski2-19/+19
Use spaces in Origen boards instead of tabs around '=' for simple property assignments, to match coding style. Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Link: https://lore.kernel.org/r/20210928084949.27939-13-krzysztof.kozlowski@canonical.com
2021-09-30ARM: dts: exynos: remove unneeded DVS voltages from PMIC on ArndaleKrzysztof Kozlowski1-3/+0
The S5M8767 PMIC does not require anymore a safe DVS voltage, if the DVS GPIO is not enabled. Although previously bindings required providing this safe DVS voltage, but since commit 04f9f068a619 ("regulator: s5m8767: Modify parsing method of the voltage table of buck2/3/4") this was ignored. Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Link: https://lore.kernel.org/r/20210928084949.27939-12-krzysztof.kozlowski@canonical.com
2021-09-30KVM: x86: SVM: add module param to control LBR virtualizationMaxim Levitsky1-1/+12
This is useful for debug and also makes it consistent with the rest of the SVM optional features. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210914154825.104886-9-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: x86: nSVM: don't copy pause related settingsMaxim Levitsky1-8/+0
According to the SDM, the CPU never modifies these settings. It loads them on VM entry and updates an internal copy instead. Also don't load them from the vmcb12 as we don't expose these features to the nested guest yet. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210914154825.104886-5-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30kvm: irqfd: avoid update unmodified entries of the routingLongpeng(Mike)1-0/+9
All of the irqfds would to be updated when update the irq routing, it's too expensive if there're too many irqfds. However we can reduce the cost by avoid some unnecessary updates. For irqs of MSI type on X86, the update can be saved if the msi values are not change. The vfio migration could receives benefit from this optimi- zaiton. The test VM has 128 vcpus and 8 VF (with 65 vectors enabled), so the VM has more than 520 irqfds. We mesure the cost of the vfio_msix_enable (in QEMU, it would set routing for each irqfd) for each VF, and we can see the total cost can be significantly reduced. Origin Apply this Patch 1st 8 4 2nd 15 5 3rd 22 6 4th 24 6 5th 36 7 6th 44 7 7th 51 8 8th 58 8 Total 258ms 51ms We're also tring to optimize the QEMU part [1], but it's still worth to optimize the KVM to gain more benefits. [1] https://lists.gnu.org/archive/html/qemu-devel/2021-08/msg04215.html Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com> Message-Id: <20210827080003.2689-1-longpeng2@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: X86: Don't check unsync if the original spte is writibleLai Jiangshan1-2/+2
If the original spte is writable, the target gfn should not be the gfn of synchronized shadowpage and can continue to be writable. When !can_unsync, speculative must be false. So when the check of "!can_unsync" is removed, we need to move the label of "out" up. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210918005636.3675-11-jiangshanlai@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: X86: Don't unsync pagetables when speculativeLai Jiangshan3-3/+8
We'd better only unsync the pagetable when there just was a really write fault on a level-1 pagetable. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210918005636.3675-10-jiangshanlai@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: X86: Remove FNAME(update_pte)Lai Jiangshan1-9/+1
Its solo caller is changed to use FNAME(prefetch_gpte) directly. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210918005636.3675-9-jiangshanlai@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: X86: Zap the invalid list after remote tlb flushingLai Jiangshan1-1/+1
In mmu_sync_children(), it can zap the invalid list after remote tlb flushing. Emptifying the invalid list ASAP might help reduce a remote tlb flushing in some cases. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210918005636.3675-8-jiangshanlai@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: X86: Change kvm_sync_page() to return true when remote flush is neededLai Jiangshan2-19/+23
Currently kvm_sync_page() returns true when there is any present spte. But the return value is ignored in the callers. Changing kvm_sync_page() to return true when remote flush is needed and changing mmu->sync_page() not to directly flush can combine and reduce remote flush requests. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210918005636.3675-7-jiangshanlai@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: X86: Remove kvm_mmu_flush_or_zap()Lai Jiangshan1-20/+6
Because local_flush is useless, kvm_mmu_flush_or_zap() can be removed and kvm_mmu_remote_flush_or_zap is used instead. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210918005636.3675-6-jiangshanlai@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: X86: Don't flush current tlb on shadow page modificationLai Jiangshan2-6/+0
After any shadow page modification, flushing tlb only on current VCPU is weird due to other VCPU's tlb might still be stale. In other words, if there is any mandatory tlb-flushing after shadow page modification, SET_SPTE_NEED_REMOTE_TLB_FLUSH or remote_flush should be set and the tlbs of all VCPUs should be flushed. There is not point to only flush current tlb except when the request is from vCPU's or pCPU's activities. If there was any bug that mandatory tlb-flushing is required and SET_SPTE_NEED_REMOTE_TLB_FLUSH/remote_flush is failed to set, this patch would expose the bug in a more destructive way. The related code paths are checked and no missing SET_SPTE_NEED_REMOTE_TLB_FLUSH is found yet. Currently, there is no optional tlb-flushing after sync page related code is changed to flush tlb timely. So we can just remove these local flushing code. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210918005636.3675-5-jiangshanlai@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: x86/mmu: Complete prefetch for trailing SPTEs for direct, legacy MMUSean Christopherson1-1/+3
Make a final call to direct_pte_prefetch_many() if there are "trailing" SPTEs to prefetch, i.e. SPTEs for GFNs following the faulting GFN. The call to direct_pte_prefetch_many() in the loop only handles the case where there are !PRESENT SPTEs preceding a PRESENT SPTE. E.g. if the faulting GFN is a multiple of 8 (the prefetch size) and all SPTEs for the following GFNs are !PRESENT, the loop will terminate with "start = sptep+1" and not prefetch any SPTEs. Prefetching trailing SPTEs as intended can drastically reduce the number of guest page faults, e.g. accessing the first byte of every 4kb page in a 6gb chunk of virtual memory, in a VM with 8gb of preallocated memory, the number of pf_fixed events observed in L0 drops from ~1.75M to <0.27M. Note, this only affects memory that is backed by 4kb pages as KVM doesn't prefetch when installing hugepages. Shadow paging prefetching is not affected as it does not batch the prefetches due to the need to process the corresponding guest PTE. The TDP MMU is not affected because it doesn't have prefetching, yet... Fixes: 957ed9effd80 ("KVM: MMU: prefetch ptes when intercepted guest #PF") Cc: Sergey Senozhatsky <senozhatsky@google.com> Cc: Ben Gardon <bgardon@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210818235615.2047588-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: x86: Manually retrieve CPUID.0x1 when getting FMS for RESET/INITSean Christopherson1-7/+5
Manually look for a CPUID.0x1 entry instead of bouncing through kvm_cpuid() when retrieving the Family-Model-Stepping information for vCPU RESET/INIT. This fixes a potential undefined behavior bug due to kvm_cpuid() using the uninitialized "dummy" param as the ECX _input_, a.k.a. the index. A more minimal fix would be to simply zero "dummy", but the extra work in kvm_cpuid() is wasteful, and KVM should be treating the FMS retrieval as an out-of-band access, e.g. same as how KVM computes guest.MAXPHYADDR. Both Intel's SDM and AMD's APM describe the RDX value at RESET/INIT as holding the CPU's FMS information, not as holding CPUID.0x1.EAX. KVM's usage of CPUID entries to get FMS is simply a pragmatic approach to avoid having yet another way for userspace to provide inconsistent data. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Jim Mattson <jmattson@google.com> Message-Id: <20210929222426.1855730-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: x86: WARN on non-zero CRs at RESET to detect improper initalizationSean Christopherson1-0/+10
WARN if CR0, CR3, or CR4 are non-zero at RESET, which given the current KVM implementation, really means WARN if they're not zeroed at vCPU creation. VMX in particular has several ->set_*() flows that read other registers to handle side effects, and because those flows are common to RESET and INIT, KVM subtly relies on emulated/virtualized registers to be zeroed at vCPU creation in order to do the right thing at RESET. Use CRs as a sentinel because they are most likely to be written as side effects, and because KVM specifically needs CR0.PG and CR0.PE to be '0' to correctly reflect the state of the vCPU's MMU. CRs are also loaded and stored from/to the VMCS, and so adds some level of coverage to verify that KVM doesn't conflate zero-allocating the VMCS with properly initializing the VMCS with VMWRITEs. Note, '0' is somewhat arbitrary, vCPU creation can technically stuff any value for a register so long as it's coherent with respect to the current vCPU state. In practice, '0' works for all registers and is convenient. Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210921000303.400537-11-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: SVM: Move RESET emulation to svm_vcpu_reset()Sean Christopherson3-16/+21
Move RESET emulation for SVM vCPUs to svm_vcpu_reset(), and drop an extra init_vmcb() from svm_create_vcpu() in the process. Hopefully KVM will someday expose a dedicated RESET ioctl(), and in the meantime separating "create" from "RESET" is a nice cleanup. Keep the call to svm_switch_vmcb() so that misuse of svm->vmcb at worst breaks the guest, e.g. premature accesses doesn't cause a NULL pointer dereference. Cc: Reiji Watanabe <reijiw@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210921000303.400537-10-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: VMX: Move RESET emulation to vmx_vcpu_reset()Sean Christopherson1-31/+32
Move vCPU RESET emulation, including initializating of select VMCS state, to vmx_vcpu_reset(). Drop the open coded "vCPU load" sequence, as ->vcpu_reset() is invoked while the vCPU is properly loaded (which is kind of the point of ->vcpu_reset()...). Hopefully KVM will someday expose a dedicated RESET ioctl(), and in the meantime separating "create" from "RESET" is a nice cleanup. Deferring VMCS initialization is effectively a nop as it's impossible to safely access the VMCS between the current call site and its new home, as both the vCPU and the pCPU are put immediately after init_vmcs(), i.e. the VMCS isn't guaranteed to be loaded. Note, task preemption is not a problem as vmx_sched_in() _can't_ touch the VMCS as ->sched_in() is invoked before the vCPU, and thus VMCS, is reloaded. I.e. the preemption path also can't consume VMCS state. Cc: Reiji Watanabe <reijiw@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210921000303.400537-9-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: VMX: Drop explicit zeroing of MSR guest values at vCPU creationSean Christopherson1-5/+1
Don't zero out user return and nested MSRs during vCPU creation, and instead rely on vcpu_vmx being zero-allocated. Explicitly zeroing MSRs is not wrong, and is in fact necessary if KVM ever emulates vCPU RESET outside of vCPU creation, but zeroing only a subset of MSRs is confusing. Poking directly into KVM's backing is also undesirable in that it doesn't scale and is error prone. Ideally KVM would have a common RESET path for all MSRs, e.g. by expanding kvm_set_msr(), which would obviate the need for this out-of-bad code (to support standalone RESET). No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210921000303.400537-8-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: x86: Fold fx_init() into kvm_arch_vcpu_create()Sean Christopherson1-12/+4
Move the few bits of relevant fx_init() code into kvm_arch_vcpu_create(), dropping the superfluous check on vcpu->arch.guest_fpu that was blindly and wrongly added by commit ed02b213098a ("KVM: SVM: Guest FPU state save/restore not needed for SEV-ES guest"). Note, KVM currently allocates and then frees FPU state for SEV-ES guests, rather than avoid the allocation in the first place. While that approach is inarguably inefficient and unnecessary, it's a cleanup for the future. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210921000303.400537-7-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: x86: Remove defunct setting of XCR0 for guest during vCPU createSean Christopherson1-6/+1
Drop code to initialize XCR0 during fx_init(), a.k.a. vCPU creation, as XCR0 has been initialized during kvm_vcpu_reset() (for RESET) since commit a554d207dc46 ("KVM: X86: Processor States following Reset or INIT"). Back when XCR0 support was added by commit 2acf923e38fb ("KVM: VMX: Enable XSAVE/XRSTOR for guest"), KVM didn't differentiate between RESET and INIT. Ignoring the fact that calling fx_init() for INIT is obviously wrong, e.g. FPU state after INIT is not the same as after RESET, setting XCR0 in fx_init() was correct. Eventually fx_init() got moved to kvm_arch_vcpu_init(), a.k.a. vCPU creation (ignore the terrible name) by commit 0ee6a5172573 ("x86/fpu, kvm: Simplify fx_init()"). Finally, commit 95a0d01eef7a ("KVM: x86: Move all vcpu init code into kvm_arch_vcpu_create()") killed off kvm_arch_vcpu_init(), leaving behind the oddity of redundant setting of guest state during vCPU creation. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210921000303.400537-6-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: x86: Remove defunct setting of CR0.ET for guests during vCPU createSean Christopherson1-2/+0
Drop code to set CR0.ET for the guest during initialization of the guest FPU. The code was added as a misguided bug fix by commit 380102c8e431 ("KVM Set the ET flag in CR0 after initializing FX") to resolve an issue where vcpu->cr0 (now vcpu->arch.cr0) was not correctly initialized on SVM systems. While init_vmcb() did set CR0.ET, it only did so in the VMCB, and subtly did not update vcpu->cr0. Stuffing CR0.ET worked around the immediate problem, but did not fix the real bug of vcpu->cr0 and the VMCB being out of sync. That underlying bug was eventually remedied by commit 18fa000ae453 ("KVM: SVM: Reset cr0 properly on vcpu reset"). No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210921000303.400537-5-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: x86: Do not mark all registers as avail/dirty during RESET/INITSean Christopherson2-2/+3
Do not blindly mark all registers as available+dirty at RESET/INIT, and instead rely on writes to registers to go through the proper mutators or to explicitly mark registers as dirty. INIT in particular does not blindly overwrite all registers, e.g. select bits in CR0 are preserved across INIT, thus marking registers available+dirty without first reading the register from hardware is incorrect. In practice this is a benign bug as KVM doesn't let the guest control CR0 bits that are preserved across INIT, and all other true registers are explicitly written during the RESET/INIT flows. The PDPTRs and EX_INFO "registers" are not explicitly written, but accessing those values during RESET/INIT is nonsensical and would be a KVM bug regardless of register caching. Fixes: 66f7b72e1171 ("KVM: x86: Make register state after reset conform to specification") [sean: !!! NOT FOR STABLE !!!] Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210921000303.400537-4-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: x86: Simplify retrieving the page offset when loading PDTPRsSean Christopherson1-2/+2
Replace impressively complex "logic" for computing the page offset from CR3 when loading PDPTRs. Unlike other paging modes, the address held in CR3 for PAE paging is 32-byte aligned, i.e. occupies bits 31:5, thus bits 11:5 need to be used as the offset from the gfn when reading PDPTRs. The existing calculation originated in commit 1342d3536d6a ("[PATCH] KVM: MMU: Load the pae pdptrs on cr3 change like the processor does"), which read the PDPTRs from guest memory as individual 8-byte loads. At the time, the so called "offset" was the base index of PDPTR0 as a _u64_, not a byte offset. Naming aside, the computation was useful and arguably simplified the overall flow. Unfortunately, when commit 195aefde9cc2 ("KVM: Add general accessors to read and write guest memory") added accessors with offsets at byte granularity, the cleverness of the original code was lost and KVM was left with convoluted code for a simple operation. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210831164224.1119728-4-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: x86: Subsume nested GPA read helper into load_pdptrs()Sean Christopherson2-41/+18
Open code the call to mmu->translate_gpa() when loading nested PDPTRs and kill off the existing helper, kvm_read_guest_page_mmu(), to discourage incorrect use. Reading guest memory straight from an L2 GPA is extremely rare (as evidenced by the lack of users), as very few constructs in x86 specify physical addresses, even fewer are virtualized by KVM, and even fewer yet require emulation of L2 by L0 KVM. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210831164224.1119728-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30kvm: rename KVM_MAX_VCPU_ID to KVM_MAX_VCPU_IDSJuergen Gross9-11/+11
KVM_MAX_VCPU_ID is not specifying the highest allowed vcpu-id, but the number of allowed vcpu-ids. This has already led to confusion, so rename KVM_MAX_VCPU_ID to KVM_MAX_VCPU_IDS to make its semantics more clear Suggested-by: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210913135745.13944-3-jgross@suse.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30Revert "x86/kvm: fix vcpu-id indexed array sizes"Juergen Gross2-3/+3
This reverts commit 76b4f357d0e7d8f6f0013c733e6cba1773c266d3. The commit has the wrong reasoning, as KVM_MAX_VCPU_ID is not defining the maximum allowed vcpu-id as its name suggests, but the number of vcpu-ids. So revert this patch again. Suggested-by: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210913135745.13944-2-jgross@suse.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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