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
