Messages in this thread | ![/](/images/icornerl.gif) | | Subject | Re: [PATCH 1/2] KVM: x86: introduce definitions to support static calls for kvm_x86_ops | From | Jason Baron <> | Date | Wed, 13 Jan 2021 11:16:38 -0500 |
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On 1/13/21 7:53 AM, Paolo Bonzini wrote: > On 11/01/21 17:57, Jason Baron wrote: >> +#define DEFINE_KVM_OPS_STATIC_CALL(func) \ >> + DEFINE_STATIC_CALL_NULL(kvm_x86_##func, \ >> + *(((struct kvm_x86_ops *)0)->func)) >> +#define DEFINE_KVM_OPS_STATIC_CALLS() \ >> + FOREACH_KVM_X86_OPS(DEFINE_KVM_OPS_STATIC_CALL) > > Something wrong here?
Hmmm...not sure what you are getting at here.
> >> +#define DECLARE_KVM_OPS_STATIC_CALL(func) \ >> + DECLARE_STATIC_CALL(kvm_x86_##func, \ >> + *(((struct kvm_x86_ops *)0)->func)) >> +#define DECLARE_KVM_OPS_STATIC_CALLS() \ >> + FOREACH_KVM_X86_OPS(DECLARE_KVM_OPS_STATIC_CALL) >> + >> +#define KVM_OPS_STATIC_CALL_UPDATE(func) \ >> + static_call_update(kvm_x86_##func, kvm_x86_ops.func) >> +#define KVM_OPS_STATIC_CALL_UPDATES() \ >> + FOREACH_KVM_X86_OPS(KVM_OPS_STATIC_CALL_UPDATE) >> + >> struct kvm_x86_ops { >> int (*hardware_enable)(void); >> void (*hardware_disable)(void); >> @@ -1326,6 +1385,12 @@ extern u64 __read_mostly host_efer; >> extern bool __read_mostly allow_smaller_maxphyaddr; >> extern struct kvm_x86_ops kvm_x86_ops; >> +DECLARE_KVM_OPS_STATIC_CALLS(); >> +static inline void kvm_ops_static_call_update(void) >> +{ >> + KVM_OPS_STATIC_CALL_UPDATES(); >> +} > > This would become > > #define KVM_X86_OP(func) \ > DECLARE_STATIC_CALL(kvm_x86_##func, \ > *(((struct kvm_x86_ops *)0)->func)); > > #include <asm/kvm-x86-ops.h> > > static inline void kvm_ops_static_call_update(void) > { > #define KVM_X86_OP(func) \ > static_call_update(kvm_x86_##func, kvm_x86_ops.func) > #include <asm/kvm-x86-ops.h> > } > > If you need to choose between DECLARE_STATIC_CALL_NULL and DECLARE_STATIC_CALL, you can have kvm-x86-ops.h use one of two macros KVM_X86_OP_NULL and > KVM_X86_OP. > > #define KVM_X86_OP(func) \ > DECLARE_STATIC_CALL(kvm_x86_##func, \ > *(((struct kvm_x86_ops *)0)->func)); > > #define KVM_X86_OP_NULL(func) \ > DECLARE_STATIC_CALL_NULL(kvm_x86_##func, \ > *(((struct kvm_x86_ops *)0)->func)); > > #include <asm/kvm-x86-ops.h> > > ... > > #define KVM_X86_OP(func) \ > static_call_update(kvm_x86_##func, kvm_x86_ops.func) > #define KVM_X86_OP_NULL(func) \ > static_call_update(kvm_x86_##func, kvm_x86_ops.func) > #include <asm/kvm-x86-ops.h> > > In that case vmx.c and svm.c could define KVM_X86_OP_NULL to an empty string and list the optional callbacks manually. >
Ok, yes, this all makes sense. So I looked at vmx/svm definitions and I see that there are 5 definitions that are common that don't use the vmx or svm prefix:
.update_exception_bitmap = update_exception_bitmap, .enable_nmi_window = enable_nmi_window, .enable_irq_window = enable_irq_window, .update_cr8_intercept = update_cr8_intercept, .enable_smi_window = enable_smi_window,
8 are specific to vmx that don't use the vmx prefix:
.hardware_unsetup = hardware_unsetup, .hardware_enable = hardware_enable, .hardware_disable = hardware_disable, .cpu_has_accelerated_tpr = report_flexpriority, .dy_apicv_has_pending_interrupt = pi_has_pending_interrupt, .has_wbinvd_exit = cpu_has_vmx_wbinvd_exit, .update_pi_irte = pi_update_irte, .complete_emulated_msr = kvm_complete_insn_gp,
and finally 7 specific to svm that don't use the svm prefix:
.get_cs_db_l_bits = kvm_get_cs_db_l_bits, .handle_exit = handle_exit, .skip_emulated_instruction = skip_emulated_instruction, .update_emulated_instruction = NULL, .sync_pir_to_irr = kvm_lapic_find_highest_irr, .apicv_post_state_restore = avic_post_state_restore, .request_immediate_exit = __kvm_request_immediate_exit,
So we could set all of these to empty definitions and specifically add the callbacks manually as you suggested. Or we could have 4 categories of macros:
1) KVM_X86_OP() - for the usual case where we have the 'svm' or 'vmx' prefix.
2) KVM_X86_OP_NULL() - for the case where both svm and vmx want to over-ride.
For the remaining cases I was thinking of having the VMX code and svm code, add a define for 'VMX' or 'SVM' respectively and then we could mark the vmx specific ones by adding something like this to asm/kvm-x86-ops.h:
#ifndef VMX #define KVM_X86_OP_UNLESS_VMX(func) \ KVM_X86_OP(func) #else #define KVM_X86_OP_UNLESS_VMX(func) #endif
and similarly for the svm specific ones:
#ifndef SVM #define KVM_X86_OP_UNLESS_SVM(func) \ KVM_X86_OP(func) #else #define KVM_X86_OP_UNLESS_SVM(func) #endif
So in vmx.c you would have:
#define X86_OP(func) .func = vmx_##func, #define VMX 1 #include "kvm-x86-ops.h"
Or we could just use the KVM_X86_OP_NULL() macro for anything that doesn't have a 'svm' or 'vmx' prefix as I think you were suggesting? In that case I think there would then be 13 manual additions for vmx and 12 for svm.
Thanks,
-Jason
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