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charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250227_163353_271886_C7D72517 X-CRM114-Status: GOOD ( 16.74 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2/27/2025 3:03 PM, Easwar Hariharan wrote: > On 2/26/2025 3:07 PM, Nuno Das Neves wrote: >> Factor out the check for enabling auto eoi, to be reused in root >> partition code. >> >> Signed-off-by: Nuno Das Neves >> --- >> drivers/hv/hv.c | 12 +----------- >> include/asm-generic/mshyperv.h | 13 +++++++++++++ >> 2 files changed, 14 insertions(+), 11 deletions(-) >> > > > >> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h >> index 258034dfd829..1f46d19a16aa 100644 >> --- a/include/asm-generic/mshyperv.h >> +++ b/include/asm-generic/mshyperv.h >> @@ -77,6 +77,19 @@ extern u64 hv_do_fast_hypercall16(u16 control, u64 input1, u64 input2); >> bool hv_isolation_type_snp(void); >> bool hv_isolation_type_tdx(void); >> >> +/* >> + * On architectures where Hyper-V doesn't support AEOI (e.g., ARM64), >> + * it doesn't provide a recommendation flag and AEOI must be disabled. >> + */ >> +static inline bool hv_recommend_using_aeoi(void) >> +{ >> +#ifdef HV_DEPRECATING_AEOI_RECOMMENDED >> + return !(ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED); >> +#else >> + return false; >> +#endif >> +} >> + > > I must be missing something very basic here, and if so, I apologize, and please enlighten me. > > HV_DEPRECATING_AEOI_RECOMMENDED is defined as BIT(9) in include/hyperv/hvgdk_mini.h, and > asm-generic/mshyperv.h includes that via include/hyperv/hvhdk.h. > > If this is the case, when would HV_DEPRECATING_AEOI_RECOMMENDED ever be not defined? > If it's always defined, do we need the #ifdef? > HV_DEPRECATING_AEOI_RECOMMENDED is only defined on x86 (it used to live in x86 hyperv-tlfs.h). It lives inside a #if defined(CONFIG_X86) block in hvgdk_mini.h. It is a bit confusing since it is surrounded by other x86-only definitions which are prefixed with HV_X64_. Thanks Nuno > Thanks, > Easwar (he/him)