2023-12-07 00:12:18

by Dionna Amalie Glaze

Subject: [PATCH] kvm: x86: use a uapi-friendly macro for BIT

Change uapi header uses of BIT to instead use the uapi/linux/const.h bit
macros, since BIT is not defined in uapi headers.

The PMU mask uses _BITUL since it targets a 32 bit flag field, whereas
the longmode definition is meant for a 64 bit flag field.

Cc: Sean Christophersen <[email protected]>
Cc: Paolo Bonzini <[email protected]>

Signed-off-by: Dionna Glaze <[email protected]>
---
arch/x86/include/uapi/asm/kvm.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index 1a6a1f987949..a8955efeef09 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -7,6 +7,7 @@
*
*/

+#include <linux/const.h>
#include <linux/types.h>
#include <linux/ioctl.h>
#include <linux/stddef.h>
@@ -526,7 +527,7 @@ struct kvm_pmu_event_filter {
#define KVM_PMU_EVENT_ALLOW 0
#define KVM_PMU_EVENT_DENY 1

-#define KVM_PMU_EVENT_FLAG_MASKED_EVENTS BIT(0)
+#define KVM_PMU_EVENT_FLAG_MASKED_EVENTS _BITUL(0)
#define KVM_PMU_EVENT_FLAGS_VALID_MASK (KVM_PMU_EVENT_FLAG_MASKED_EVENTS)

/*
@@ -560,6 +561,6 @@ struct kvm_pmu_event_filter {
#define KVM_VCPU_TSC_OFFSET 0 /* attribute for the TSC offset */

/* x86-specific KVM_EXIT_HYPERCALL flags. */
-#define KVM_EXIT_HYPERCALL_LONG_MODE BIT(0)
+#define KVM_EXIT_HYPERCALL_LONG_MODE _BITULL(0)

#endif /* _ASM_X86_KVM_H */
--
2.43.0.rc2.451.g8631bc7472-goog

2023-12-12 15:28:26

by Sean Christopherson

Subject: Re: [PATCH] kvm: x86: use a uapi-friendly macro for BIT

On Thu, Dec 07, 2023, Dionna Glaze wrote:
> Change uapi header uses of BIT to instead use the uapi/linux/const.h bit
> macros, since BIT is not defined in uapi headers.
>
> The PMU mask uses _BITUL since it targets a 32 bit flag field, whereas
> the longmode definition is meant for a 64 bit flag field.
>
> Cc: Sean Christophersen <[email protected]>
> Cc: Paolo Bonzini <[email protected]>
>
> Signed-off-by: Dionna Glaze <[email protected]>
> ---
> arch/x86/include/uapi/asm/kvm.h | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
> index 1a6a1f987949..a8955efeef09 100644
> --- a/arch/x86/include/uapi/asm/kvm.h
> +++ b/arch/x86/include/uapi/asm/kvm.h
> @@ -7,6 +7,7 @@
> *
> */
>
> +#include <linux/const.h>
> #include <linux/types.h>
> #include <linux/ioctl.h>
> #include <linux/stddef.h>
> @@ -526,7 +527,7 @@ struct kvm_pmu_event_filter {
> #define KVM_PMU_EVENT_ALLOW 0
> #define KVM_PMU_EVENT_DENY 1
>
> -#define KVM_PMU_EVENT_FLAG_MASKED_EVENTS BIT(0)
> +#define KVM_PMU_EVENT_FLAG_MASKED_EVENTS _BITUL(0)

It's not just BIT(), won't BIT_ULL() and GENMASK_ULL() also be problematic? And
sadly, I don't see an existing equivalent for GENMASK_ULL().

2023-12-12 16:07:56

by Paolo Bonzini

Subject: Re: [PATCH] kvm: x86: use a uapi-friendly macro for BIT

On 12/12/23 16:27, Sean Christopherson wrote:
>> -#define KVM_PMU_EVENT_FLAG_MASKED_EVENTS BIT(0)
>> +#define KVM_PMU_EVENT_FLAG_MASKED_EVENTS _BITUL(0)
> It's not just BIT(), won't BIT_ULL() and GENMASK_ULL() also be problematic? And
> sadly, I don't see an existing equivalent for GENMASK_ULL().

BIT_ULL() is easy enough, as you point out:

@@ -550,7 +550,7 @@ struct kvm_pmu_event_filter {
(GENMASK_ULL(7, 0) | GENMASK_ULL(35, 32))
#define KVM_PMU_MASKED_ENTRY_UMASK_MASK (GENMASK_ULL(63, 56))
#define KVM_PMU_MASKED_ENTRY_UMASK_MATCH (GENMASK_ULL(15, 8))
-#define KVM_PMU_MASKED_ENTRY_EXCLUDE (BIT_ULL(55))
+#define KVM_PMU_MASKED_ENTRY_EXCLUDE (_BITULL(55))
#define KVM_PMU_MASKED_ENTRY_UMASK_MASK_SHIFT (56)

/* for KVM_{GET,SET,HAS}_DEVICE_ATTR */

And I'll squash it into Dionna's patch since she has already a conversion
for KVM_EXIT_HYPERCALL_LONG_MODE. For the others, I'll send a patch.

Paolo