| Message ID | 20220923114259.2945-1-kunyu@nfschina.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | [v3] hyperv: simplify and rename generate_guest_id | expand |
From: Li kunyu <kunyu@nfschina.com> Sent: Friday, September 23, 2022 4:43 AM > > The generate_guest_id function is more suitable for use after the > following modifications. > 1. Modify the type of the guest_id variable to u64, which is compatible > with the caller. > 2. Remove all parameters from the function, and write the parameter > (LINUX_VERSION_CODE) passed in by the actual call into the function > implementation. > 3. Rename the function to make it clearly a Hyper-V related function, > and modify it to hv_generate_guest_id. > > Signed-off-by: Li kunyu <kunyu@nfschina.com> > > -------- > v2: Fix generate_guest_id to hv_generate_guest_id. > v3: Fix [PATCH v2] asm-generic: Remove the ... to [PATCH v3] hyperv: simp > lify ... and remove extra spaces > --- > arch/arm64/hyperv/mshyperv.c | 2 +- > arch/x86/hyperv/hv_init.c | 2 +- > include/asm-generic/mshyperv.h | 12 +++++------- > 3 files changed, 7 insertions(+), 9 deletions(-) > > diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c > index bbbe351e9045..3863fd226e0e 100644 > --- a/arch/arm64/hyperv/mshyperv.c > +++ b/arch/arm64/hyperv/mshyperv.c > @@ -38,7 +38,7 @@ static int __init hyperv_init(void) > return 0; > > /* Setup the guest ID */ > - guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0); > + guest_id = hv_generate_guest_id(); > hv_set_vpreg(HV_REGISTER_GUEST_OSID, guest_id); > > /* Get the features and hints from Hyper-V */ > diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c > index 3de6d8b53367..93770791b858 100644 > --- a/arch/x86/hyperv/hv_init.c > +++ b/arch/x86/hyperv/hv_init.c > @@ -426,7 +426,7 @@ void __init hyperv_init(void) > * 1. Register the guest ID > * 2. Enable the hypercall and register the hypercall page > */ > - guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0); > + guest_id = hv_generate_guest_id(); > wrmsrl(HV_X64_MSR_GUEST_OS_ID, guest_id); > > /* Hyper-V requires to write guest os id via ghcb in SNP IVM. */ > diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h > index c05d2ce9b6cd..7f4a23cee56f 100644 > --- a/include/asm-generic/mshyperv.h > +++ b/include/asm-generic/mshyperv.h > @@ -25,6 +25,7 @@ > #include <linux/nmi.h> > #include <asm/ptrace.h> > #include <asm/hyperv-tlfs.h> > +#include <linux/version.h> Having added the #include of linux/version.h here, you should remove it from arch/arm64/hyperv/mshyperv.c and arch/x86/hyperv/hv_init.c. It shouldn't be needed any longer in those two files. Michael > > struct ms_hyperv_info { > u32 features; > @@ -105,15 +106,12 @@ static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size, > } > > /* Generate the guest OS identifier as described in the Hyper-V TLFS */ > -static inline __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version, > - __u64 d_info2) > +static inline u64 hv_generate_guest_id(void) > { > - __u64 guest_id = 0; > + u64 guest_id; > > - guest_id = (((__u64)HV_LINUX_VENDOR_ID) << 48); > - guest_id |= (d_info1 << 48); > - guest_id |= (kernel_version << 16); > - guest_id |= d_info2; > + guest_id = (((u64)HV_LINUX_VENDOR_ID) << 48); > + guest_id |= (((u64)LINUX_VERSION_CODE) << 16); > > return guest_id; > } > -- > 2.18.2
Fri, 23 Sep 2022 19:42:59 +0800 Li kunyu <kunyu@nfschina.com>: > +++ b/include/asm-generic/mshyperv.h > +#include <linux/version.h> A very long time ago I removed most usage of version.h AFAIR, so that changing uname -r will dirty just a tiny amount of objects. But, this header is always coming back, like bad weed. Please reconsider the suggested approach. Thanks, Olaf
From: Olaf Hering <olaf@aepfle.de> Sent: Friday, September 23, 2022 2:09 PM > > Fri, 23 Sep 2022 19:42:59 +0800 Li kunyu <kunyu@nfschina.com>: > > > +++ b/include/asm-generic/mshyperv.h > > +#include <linux/version.h> > > A very long time ago I removed most usage of version.h AFAIR, > so that changing uname -r will dirty just a tiny amount of objects. > > But, this header is always coming back, like bad weed. > > Please reconsider the suggested approach. Could you elaborate? This code is getting the Linux kernel version to pass to the hypervisor for later diagnostic purposes. In a large cloud environment like Azure, it's helpful sometimes to be able to correlate emerging fleet-wide issues to particular kernel versions. The Hyper-V code in Linux has been using LINUX_VERSION_CODE this way for the past 10 years, so this isn't new. Is there a more preferred mechanism for kernel code to get its version? Michael
Sat, 24 Sep 2022 05:31:34 +0000 "Michael Kelley (LINUX)" <mikelley@microsoft.com>: > From: Olaf Hering <olaf@aepfle.de> Sent: Friday, September 23, 2022 2:09 PM > > A very long time ago I removed most usage of version.h AFAIR, > Could you elaborate? It is the cost of 'make LOCALVERSION=x' vs. 'make LOCALVERSION=y'. Too many drivers will be recompiled for no good reason as of today. I claim no consumer below drivers/ and sound/ has a valid usecase for version.h. But, someone else has to take the energy and argue them out of the tree. With the proposed change every consumer of asm-generic/mshyperv.h will be dirty, see 'touch include/asm-generic/mshyperv.h' for the impact. Therefore I think only the two existing c files should include this header, in case the provided information has a true value for the consumer. Olaf
From: Olaf Hering <olaf@aepfle.de> Sent: Monday, September 26, 2022 12:57 AM > > Sat, 24 Sep 2022 05:31:34 +0000 "Michael Kelley (LINUX)" <mikelley@microsoft.com>: > > > From: Olaf Hering <olaf@aepfle.de> Sent: Friday, September 23, 2022 2:09 PM > > > > A very long time ago I removed most usage of version.h AFAIR, > > Could you elaborate? > > It is the cost of 'make LOCALVERSION=x' vs. 'make LOCALVERSION=y'. > > Too many drivers will be recompiled for no good reason as of today. > I claim no consumer below drivers/ and sound/ has a valid usecase for version.h. > But, someone else has to take the energy and argue them out of the tree. > > With the proposed change every consumer of asm-generic/mshyperv.h will be dirty, > see 'touch include/asm-generic/mshyperv.h' for the impact. Therefore I think > only the two existing c files should include this header, in case the provided > information has a true value for the consumer. > Thanks, Olaf. That makes sense and I agree. Li Kunyu -- that means you should "undo" part of your patch. Keep the use of LINUX_VERSION_CODE and the #include of <linux/version.h> in the two .c files, and pass LINUX_VERSION_CODE as an argument to hv_generate_guest_id(). Remove the #include of <linux/version.h> from include/asm-generic/mshyperv.h. Michael
diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c index bbbe351e9045..3863fd226e0e 100644 --- a/arch/arm64/hyperv/mshyperv.c +++ b/arch/arm64/hyperv/mshyperv.c @@ -38,7 +38,7 @@ static int __init hyperv_init(void) return 0; /* Setup the guest ID */ - guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0); + guest_id = hv_generate_guest_id(); hv_set_vpreg(HV_REGISTER_GUEST_OSID, guest_id); /* Get the features and hints from Hyper-V */ diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c index 3de6d8b53367..93770791b858 100644 --- a/arch/x86/hyperv/hv_init.c +++ b/arch/x86/hyperv/hv_init.c @@ -426,7 +426,7 @@ void __init hyperv_init(void) * 1. Register the guest ID * 2. Enable the hypercall and register the hypercall page */ - guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0); + guest_id = hv_generate_guest_id(); wrmsrl(HV_X64_MSR_GUEST_OS_ID, guest_id); /* Hyper-V requires to write guest os id via ghcb in SNP IVM. */ diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h index c05d2ce9b6cd..7f4a23cee56f 100644 --- a/include/asm-generic/mshyperv.h +++ b/include/asm-generic/mshyperv.h @@ -25,6 +25,7 @@ #include <linux/nmi.h> #include <asm/ptrace.h> #include <asm/hyperv-tlfs.h> +#include <linux/version.h> struct ms_hyperv_info { u32 features; @@ -105,15 +106,12 @@ static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size, } /* Generate the guest OS identifier as described in the Hyper-V TLFS */ -static inline __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version, - __u64 d_info2) +static inline u64 hv_generate_guest_id(void) { - __u64 guest_id = 0; + u64 guest_id; - guest_id = (((__u64)HV_LINUX_VENDOR_ID) << 48); - guest_id |= (d_info1 << 48); - guest_id |= (kernel_version << 16); - guest_id |= d_info2; + guest_id = (((u64)HV_LINUX_VENDOR_ID) << 48); + guest_id |= (((u64)LINUX_VERSION_CODE) << 16); return guest_id; }
The generate_guest_id function is more suitable for use after the following modifications. 1. Modify the type of the guest_id variable to u64, which is compatible with the caller. 2. Remove all parameters from the function, and write the parameter (LINUX_VERSION_CODE) passed in by the actual call into the function implementation. 3. Rename the function to make it clearly a Hyper-V related function, and modify it to hv_generate_guest_id. Signed-off-by: Li kunyu <kunyu@nfschina.com> -------- v2: Fix generate_guest_id to hv_generate_guest_id. v3: Fix [PATCH v2] asm-generic: Remove the ... to [PATCH v3] hyperv: simp lify ... and remove extra spaces --- arch/arm64/hyperv/mshyperv.c | 2 +- arch/x86/hyperv/hv_init.c | 2 +- include/asm-generic/mshyperv.h | 12 +++++------- 3 files changed, 7 insertions(+), 9 deletions(-)