| Message ID | 20210922000533.713300-6-seanjc@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | perf: KVM: Fix, optimize, and clean up callbacks | expand |
On 22/09/21 02:05, Sean Christopherson wrote: > Drop "support" for guest callbacks from architctures that don't implement > the guest callbacks. Future patches will convert the callbacks to > static_call; rather than churn a bunch of arch code (that was presumably > copy+pasted from x86), remove it wholesale as it's useless and at best > wasting cycles. > > A future patch will also add a Kconfig to force architcture to opt into > the callbacks to make it more difficult for uses "support" to sneak in in > the future. > > No functional change intended. > > Signed-off-by: Sean Christopherson <seanjc@google.com> > --- > arch/arm/kernel/perf_callchain.c | 33 ++++------------------------- > arch/csky/kernel/perf_callchain.c | 12 ----------- > arch/nds32/kernel/perf_event_cpu.c | 34 ++++-------------------------- > arch/riscv/kernel/perf_callchain.c | 13 ------------ > 4 files changed, 8 insertions(+), 84 deletions(-) > > diff --git a/arch/arm/kernel/perf_callchain.c b/arch/arm/kernel/perf_callchain.c > index 1626dfc6f6ce..bc6b246ab55e 100644 > --- a/arch/arm/kernel/perf_callchain.c > +++ b/arch/arm/kernel/perf_callchain.c > @@ -62,14 +62,8 @@ user_backtrace(struct frame_tail __user *tail, > void > perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) > { > - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); > struct frame_tail __user *tail; > > - if (guest_cbs && guest_cbs->is_in_guest()) { > - /* We don't support guest os callchain now */ > - return; > - } > - > perf_callchain_store(entry, regs->ARM_pc); > > if (!current->mm) > @@ -99,44 +93,25 @@ callchain_trace(struct stackframe *fr, > void > perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) > { > - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); > struct stackframe fr; > > - if (guest_cbs && guest_cbs->is_in_guest()) { > - /* We don't support guest os callchain now */ > - return; > - } > - > arm_get_current_stackframe(regs, &fr); > walk_stackframe(&fr, callchain_trace, entry); > } > > unsigned long perf_instruction_pointer(struct pt_regs *regs) > { > - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); > - > - if (guest_cbs && guest_cbs->is_in_guest()) > - return guest_cbs->get_guest_ip(); > - > return instruction_pointer(regs); > } > > unsigned long perf_misc_flags(struct pt_regs *regs) > { > - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); > int misc = 0; > > - if (guest_cbs && guest_cbs->is_in_guest()) { > - if (guest_cbs->is_user_mode()) > - misc |= PERF_RECORD_MISC_GUEST_USER; > - else > - misc |= PERF_RECORD_MISC_GUEST_KERNEL; > - } else { > - if (user_mode(regs)) > - misc |= PERF_RECORD_MISC_USER; > - else > - misc |= PERF_RECORD_MISC_KERNEL; > - } > + if (user_mode(regs)) > + misc |= PERF_RECORD_MISC_USER; > + else > + misc |= PERF_RECORD_MISC_KERNEL; > > return misc; > } > diff --git a/arch/csky/kernel/perf_callchain.c b/arch/csky/kernel/perf_callchain.c > index 35318a635a5f..92057de08f4f 100644 > --- a/arch/csky/kernel/perf_callchain.c > +++ b/arch/csky/kernel/perf_callchain.c > @@ -86,13 +86,8 @@ static unsigned long user_backtrace(struct perf_callchain_entry_ctx *entry, > void perf_callchain_user(struct perf_callchain_entry_ctx *entry, > struct pt_regs *regs) > { > - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); > unsigned long fp = 0; > > - /* C-SKY does not support virtualization. */ > - if (guest_cbs && guest_cbs->is_in_guest()) > - return; > - > fp = regs->regs[4]; > perf_callchain_store(entry, regs->pc); > > @@ -111,15 +106,8 @@ void perf_callchain_user(struct perf_callchain_entry_ctx *entry, > void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, > struct pt_regs *regs) > { > - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); > struct stackframe fr; > > - /* C-SKY does not support virtualization. */ > - if (guest_cbs && guest_cbs->is_in_guest()) { > - pr_warn("C-SKY does not support perf in guest mode!"); > - return; > - } > - > fr.fp = regs->regs[4]; > fr.lr = regs->lr; > walk_stackframe(&fr, entry); > diff --git a/arch/nds32/kernel/perf_event_cpu.c b/arch/nds32/kernel/perf_event_cpu.c > index f38791960781..a78a879e7ef1 100644 > --- a/arch/nds32/kernel/perf_event_cpu.c > +++ b/arch/nds32/kernel/perf_event_cpu.c > @@ -1363,7 +1363,6 @@ void > perf_callchain_user(struct perf_callchain_entry_ctx *entry, > struct pt_regs *regs) > { > - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); > unsigned long fp = 0; > unsigned long gp = 0; > unsigned long lp = 0; > @@ -1372,11 +1371,6 @@ perf_callchain_user(struct perf_callchain_entry_ctx *entry, > > leaf_fp = 0; > > - if (guest_cbs && guest_cbs->is_in_guest()) { > - /* We don't support guest os callchain now */ > - return; > - } > - > perf_callchain_store(entry, regs->ipc); > fp = regs->fp; > gp = regs->gp; > @@ -1480,13 +1474,8 @@ void > perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, > struct pt_regs *regs) > { > - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); > struct stackframe fr; > > - if (guest_cbs && guest_cbs->is_in_guest()) { > - /* We don't support guest os callchain now */ > - return; > - } > fr.fp = regs->fp; > fr.lp = regs->lp; > fr.sp = regs->sp; > @@ -1495,32 +1484,17 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, > > unsigned long perf_instruction_pointer(struct pt_regs *regs) > { > - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); > - > - /* However, NDS32 does not support virtualization */ > - if (guest_cbs && guest_cbs->is_in_guest()) > - return guest_cbs->get_guest_ip(); > - > return instruction_pointer(regs); > } > > unsigned long perf_misc_flags(struct pt_regs *regs) > { > - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); > int misc = 0; > > - /* However, NDS32 does not support virtualization */ > - if (guest_cbs && guest_cbs->is_in_guest()) { > - if (guest_cbs->is_user_mode()) > - misc |= PERF_RECORD_MISC_GUEST_USER; > - else > - misc |= PERF_RECORD_MISC_GUEST_KERNEL; > - } else { > - if (user_mode(regs)) > - misc |= PERF_RECORD_MISC_USER; > - else > - misc |= PERF_RECORD_MISC_KERNEL; > - } > + if (user_mode(regs)) > + misc |= PERF_RECORD_MISC_USER; > + else > + misc |= PERF_RECORD_MISC_KERNEL; > > return misc; > } > diff --git a/arch/riscv/kernel/perf_callchain.c b/arch/riscv/kernel/perf_callchain.c > index 8ecfc4c128bc..1fc075b8f764 100644 > --- a/arch/riscv/kernel/perf_callchain.c > +++ b/arch/riscv/kernel/perf_callchain.c > @@ -56,13 +56,8 @@ static unsigned long user_backtrace(struct perf_callchain_entry_ctx *entry, > void perf_callchain_user(struct perf_callchain_entry_ctx *entry, > struct pt_regs *regs) > { > - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); > unsigned long fp = 0; > > - /* RISC-V does not support perf in guest mode. */ > - if (guest_cbs && guest_cbs->is_in_guest()) > - return; > - > fp = regs->s0; > perf_callchain_store(entry, regs->epc); > > @@ -79,13 +74,5 @@ static bool fill_callchain(void *entry, unsigned long pc) > void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, > struct pt_regs *regs) > { > - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); > - > - /* RISC-V does not support perf in guest mode. */ > - if (guest_cbs && guest_cbs->is_in_guest()) { > - pr_warn("RISC-V does not support perf in guest mode!"); > - return; > - } > - > walk_stackframe(NULL, regs, fill_callchain, entry); > } > Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/arm/kernel/perf_callchain.c b/arch/arm/kernel/perf_callchain.c index 1626dfc6f6ce..bc6b246ab55e 100644 --- a/arch/arm/kernel/perf_callchain.c +++ b/arch/arm/kernel/perf_callchain.c @@ -62,14 +62,8 @@ user_backtrace(struct frame_tail __user *tail, void perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) { - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); struct frame_tail __user *tail; - if (guest_cbs && guest_cbs->is_in_guest()) { - /* We don't support guest os callchain now */ - return; - } - perf_callchain_store(entry, regs->ARM_pc); if (!current->mm) @@ -99,44 +93,25 @@ callchain_trace(struct stackframe *fr, void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) { - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); struct stackframe fr; - if (guest_cbs && guest_cbs->is_in_guest()) { - /* We don't support guest os callchain now */ - return; - } - arm_get_current_stackframe(regs, &fr); walk_stackframe(&fr, callchain_trace, entry); } unsigned long perf_instruction_pointer(struct pt_regs *regs) { - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); - - if (guest_cbs && guest_cbs->is_in_guest()) - return guest_cbs->get_guest_ip(); - return instruction_pointer(regs); } unsigned long perf_misc_flags(struct pt_regs *regs) { - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); int misc = 0; - if (guest_cbs && guest_cbs->is_in_guest()) { - if (guest_cbs->is_user_mode()) - misc |= PERF_RECORD_MISC_GUEST_USER; - else - misc |= PERF_RECORD_MISC_GUEST_KERNEL; - } else { - if (user_mode(regs)) - misc |= PERF_RECORD_MISC_USER; - else - misc |= PERF_RECORD_MISC_KERNEL; - } + if (user_mode(regs)) + misc |= PERF_RECORD_MISC_USER; + else + misc |= PERF_RECORD_MISC_KERNEL; return misc; } diff --git a/arch/csky/kernel/perf_callchain.c b/arch/csky/kernel/perf_callchain.c index 35318a635a5f..92057de08f4f 100644 --- a/arch/csky/kernel/perf_callchain.c +++ b/arch/csky/kernel/perf_callchain.c @@ -86,13 +86,8 @@ static unsigned long user_backtrace(struct perf_callchain_entry_ctx *entry, void perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) { - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); unsigned long fp = 0; - /* C-SKY does not support virtualization. */ - if (guest_cbs && guest_cbs->is_in_guest()) - return; - fp = regs->regs[4]; perf_callchain_store(entry, regs->pc); @@ -111,15 +106,8 @@ void perf_callchain_user(struct perf_callchain_entry_ctx *entry, void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) { - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); struct stackframe fr; - /* C-SKY does not support virtualization. */ - if (guest_cbs && guest_cbs->is_in_guest()) { - pr_warn("C-SKY does not support perf in guest mode!"); - return; - } - fr.fp = regs->regs[4]; fr.lr = regs->lr; walk_stackframe(&fr, entry); diff --git a/arch/nds32/kernel/perf_event_cpu.c b/arch/nds32/kernel/perf_event_cpu.c index f38791960781..a78a879e7ef1 100644 --- a/arch/nds32/kernel/perf_event_cpu.c +++ b/arch/nds32/kernel/perf_event_cpu.c @@ -1363,7 +1363,6 @@ void perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) { - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); unsigned long fp = 0; unsigned long gp = 0; unsigned long lp = 0; @@ -1372,11 +1371,6 @@ perf_callchain_user(struct perf_callchain_entry_ctx *entry, leaf_fp = 0; - if (guest_cbs && guest_cbs->is_in_guest()) { - /* We don't support guest os callchain now */ - return; - } - perf_callchain_store(entry, regs->ipc); fp = regs->fp; gp = regs->gp; @@ -1480,13 +1474,8 @@ void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) { - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); struct stackframe fr; - if (guest_cbs && guest_cbs->is_in_guest()) { - /* We don't support guest os callchain now */ - return; - } fr.fp = regs->fp; fr.lp = regs->lp; fr.sp = regs->sp; @@ -1495,32 +1484,17 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, unsigned long perf_instruction_pointer(struct pt_regs *regs) { - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); - - /* However, NDS32 does not support virtualization */ - if (guest_cbs && guest_cbs->is_in_guest()) - return guest_cbs->get_guest_ip(); - return instruction_pointer(regs); } unsigned long perf_misc_flags(struct pt_regs *regs) { - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); int misc = 0; - /* However, NDS32 does not support virtualization */ - if (guest_cbs && guest_cbs->is_in_guest()) { - if (guest_cbs->is_user_mode()) - misc |= PERF_RECORD_MISC_GUEST_USER; - else - misc |= PERF_RECORD_MISC_GUEST_KERNEL; - } else { - if (user_mode(regs)) - misc |= PERF_RECORD_MISC_USER; - else - misc |= PERF_RECORD_MISC_KERNEL; - } + if (user_mode(regs)) + misc |= PERF_RECORD_MISC_USER; + else + misc |= PERF_RECORD_MISC_KERNEL; return misc; } diff --git a/arch/riscv/kernel/perf_callchain.c b/arch/riscv/kernel/perf_callchain.c index 8ecfc4c128bc..1fc075b8f764 100644 --- a/arch/riscv/kernel/perf_callchain.c +++ b/arch/riscv/kernel/perf_callchain.c @@ -56,13 +56,8 @@ static unsigned long user_backtrace(struct perf_callchain_entry_ctx *entry, void perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) { - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); unsigned long fp = 0; - /* RISC-V does not support perf in guest mode. */ - if (guest_cbs && guest_cbs->is_in_guest()) - return; - fp = regs->s0; perf_callchain_store(entry, regs->epc); @@ -79,13 +74,5 @@ static bool fill_callchain(void *entry, unsigned long pc) void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) { - struct perf_guest_info_callbacks *guest_cbs = perf_get_guest_cbs(); - - /* RISC-V does not support perf in guest mode. */ - if (guest_cbs && guest_cbs->is_in_guest()) { - pr_warn("RISC-V does not support perf in guest mode!"); - return; - } - walk_stackframe(NULL, regs, fill_callchain, entry); }
Drop "support" for guest callbacks from architctures that don't implement the guest callbacks. Future patches will convert the callbacks to static_call; rather than churn a bunch of arch code (that was presumably copy+pasted from x86), remove it wholesale as it's useless and at best wasting cycles. A future patch will also add a Kconfig to force architcture to opt into the callbacks to make it more difficult for uses "support" to sneak in in the future. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> --- arch/arm/kernel/perf_callchain.c | 33 ++++------------------------- arch/csky/kernel/perf_callchain.c | 12 ----------- arch/nds32/kernel/perf_event_cpu.c | 34 ++++-------------------------- arch/riscv/kernel/perf_callchain.c | 13 ------------ 4 files changed, 8 insertions(+), 84 deletions(-)