RE: [PATCH v2 2/5] x86: add enum for hypervisors to replace x86_hyper

From: KY Srinivasan
Date: Fri Nov 10 2017 - 15:39:22 EST




> -----Original Message-----
> From: Dmitry Torokhov [mailto:dmitry.torokhov@xxxxxxxxx]
> Sent: Friday, November 10, 2017 10:26 AM
> To: Juergen Gross <jgross@xxxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx; tglx@xxxxxxxxxxxxx; mingo@xxxxxxxxxx;
> hpa@xxxxxxxxx; x86@xxxxxxxxxx; KY Srinivasan <kys@xxxxxxxxxxxxx>;
> Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>; Stephen Hemminger
> <sthemmin@xxxxxxxxxxxxx>; akataria@xxxxxxxxxx;
> pbonzini@xxxxxxxxxx; rkrcmar@xxxxxxxxxx; boris.ostrovsky@xxxxxxxxxx;
> devel@xxxxxxxxxxxxxxxxxxxxxx; virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx;
> kvm@xxxxxxxxxxxxxxx; xen-devel@xxxxxxxxxxxxxxxxxxxx; linux-graphics-
> maintainer@xxxxxxxxxx; pv-drivers@xxxxxxxxxx;
> xdeguillard@xxxxxxxxxx; moltmann@xxxxxxxxxx; arnd@xxxxxxxx;
> gregkh@xxxxxxxxxxxxxxxxxxx; linux-input@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v2 2/5] x86: add enum for hypervisors to replace
> x86_hyper
>
> On Thu, Nov 09, 2017 at 02:27:36PM +0100, Juergen Gross wrote:
> > The x86_hyper pointer is only used for checking whether a virtual
> > device is supporting the hypervisor the system is running on.
> >
> > Use an enum for that purpose instead and drop the x86_hyper pointer.
> >
> > Cc: kys@xxxxxxxxxxxxx
> > Cc: haiyangz@xxxxxxxxxxxxx
> > Cc: sthemmin@xxxxxxxxxxxxx
> > Cc: akataria@xxxxxxxxxx
> > Cc: pbonzini@xxxxxxxxxx
> > Cc: rkrcmar@xxxxxxxxxx
> > Cc: boris.ostrovsky@xxxxxxxxxx
> > Cc: devel@xxxxxxxxxxxxxxxxxxxxxx
> > Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
> > Cc: kvm@xxxxxxxxxxxxxxx
> > Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx
> > Cc: linux-graphics-maintainer@xxxxxxxxxx
> > Cc: pv-drivers@xxxxxxxxxx
> > Cc: dmitry.torokhov@xxxxxxxxx
> > Cc: xdeguillard@xxxxxxxxxx
> > Cc: moltmann@xxxxxxxxxx
> > Cc: arnd@xxxxxxxx
> > Cc: gregkh@xxxxxxxxxxxxxxxxxxx
> > Cc: linux-input@xxxxxxxxxxxxxxx
> >
> > Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
> > ---
> > arch/x86/hyperv/hv_init.c | 2 +-
> > arch/x86/include/asm/hypervisor.h | 23 ++++++++++++++---------
> > arch/x86/kernel/cpu/hypervisor.c | 12 +++++++++---
> > arch/x86/kernel/cpu/mshyperv.c | 4 ++--
> > arch/x86/kernel/cpu/vmware.c | 4 ++--
> > arch/x86/kernel/kvm.c | 4 ++--
> > arch/x86/xen/enlighten_hvm.c | 4 ++--
> > arch/x86/xen/enlighten_pv.c | 4 ++--
> > drivers/hv/vmbus_drv.c | 2 +-
> > drivers/input/mouse/vmmouse.c | 10 ++++------
>
> Acked-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
Acked-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>

>
> > drivers/misc/vmw_balloon.c | 2 +-
> > 11 files changed, 40 insertions(+), 31 deletions(-)
> >
> > diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
> > index a5db63f728a2..a0b86cf486e0 100644
> > --- a/arch/x86/hyperv/hv_init.c
> > +++ b/arch/x86/hyperv/hv_init.c
> > @@ -113,7 +113,7 @@ void hyperv_init(void)
> > u64 guest_id;
> > union hv_x64_msr_hypercall_contents hypercall_msr;
> >
> > - if (x86_hyper != &x86_hyper_ms_hyperv)
> > + if (x86_hyper_type != X86_HYPER_MS_HYPERV)
> > return;
> >
> > /* Allocate percpu VP index */
> > diff --git a/arch/x86/include/asm/hypervisor.h
> b/arch/x86/include/asm/hypervisor.h
> > index 0eca7239a7aa..1b0a5abcd8ae 100644
> > --- a/arch/x86/include/asm/hypervisor.h
> > +++ b/arch/x86/include/asm/hypervisor.h
> > @@ -29,6 +29,16 @@
> > /*
> > * x86 hypervisor information
> > */
> > +
> > +enum x86_hypervisor_type {
> > + X86_HYPER_NATIVE = 0,
> > + X86_HYPER_VMWARE,
> > + X86_HYPER_MS_HYPERV,
> > + X86_HYPER_XEN_PV,
> > + X86_HYPER_XEN_HVM,
> > + X86_HYPER_KVM,
> > +};
> > +
> > struct hypervisor_x86 {
> > /* Hypervisor name */
> > const char *name;
> > @@ -36,6 +46,9 @@ struct hypervisor_x86 {
> > /* Detection routine */
> > uint32_t (*detect)(void);
> >
> > + /* Hypervisor type */
> > + enum x86_hypervisor_type type;
> > +
> > /* init time callbacks */
> > struct x86_hyper_init init;
> >
> > @@ -43,15 +56,7 @@ struct hypervisor_x86 {
> > struct x86_hyper_runtime runtime;
> > };
> >
> > -extern const struct hypervisor_x86 *x86_hyper;
> > -
> > -/* Recognized hypervisors */
> > -extern const struct hypervisor_x86 x86_hyper_vmware;
> > -extern const struct hypervisor_x86 x86_hyper_ms_hyperv;
> > -extern const struct hypervisor_x86 x86_hyper_xen_pv;
> > -extern const struct hypervisor_x86 x86_hyper_xen_hvm;
> > -extern const struct hypervisor_x86 x86_hyper_kvm;
> > -
> > +extern enum x86_hypervisor_type x86_hyper_type;
> > extern void init_hypervisor_platform(void);
> > #else
> > static inline void init_hypervisor_platform(void) { }
> > diff --git a/arch/x86/kernel/cpu/hypervisor.c
> b/arch/x86/kernel/cpu/hypervisor.c
> > index 22226c1bf092..bea8d3e24f50 100644
> > --- a/arch/x86/kernel/cpu/hypervisor.c
> > +++ b/arch/x86/kernel/cpu/hypervisor.c
> > @@ -26,6 +26,12 @@
> > #include <asm/processor.h>
> > #include <asm/hypervisor.h>
> >
> > +extern const struct hypervisor_x86 x86_hyper_vmware;
> > +extern const struct hypervisor_x86 x86_hyper_ms_hyperv;
> > +extern const struct hypervisor_x86 x86_hyper_xen_pv;
> > +extern const struct hypervisor_x86 x86_hyper_xen_hvm;
> > +extern const struct hypervisor_x86 x86_hyper_kvm;
> > +
> > static const __initconst struct hypervisor_x86 * const hypervisors[] =
> > {
> > #ifdef CONFIG_XEN_PV
> > @@ -41,8 +47,8 @@ static const __initconst struct hypervisor_x86 * const
> hypervisors[] =
> > #endif
> > };
> >
> > -const struct hypervisor_x86 *x86_hyper;
> > -EXPORT_SYMBOL(x86_hyper);
> > +enum x86_hypervisor_type x86_hyper_type;
> > +EXPORT_SYMBOL(x86_hyper_type);
> >
> > static inline const struct hypervisor_x86 * __init
> > detect_hypervisor_vendor(void)
> > @@ -87,6 +93,6 @@ void __init init_hypervisor_platform(void)
> > copy_array(&h->init, &x86_init.hyper, sizeof(h->init));
> > copy_array(&h->runtime, &x86_platform.hyper, sizeof(h-
> >runtime));
> >
> > - x86_hyper = h;
> > + x86_hyper_type = h->type;
> > x86_init.hyper.init_platform();
> > }
> > diff --git a/arch/x86/kernel/cpu/mshyperv.c
> b/arch/x86/kernel/cpu/mshyperv.c
> > index 6bb84d655e4b..85eb5fc180c8 100644
> > --- a/arch/x86/kernel/cpu/mshyperv.c
> > +++ b/arch/x86/kernel/cpu/mshyperv.c
> > @@ -254,9 +254,9 @@ static void __init ms_hyperv_init_platform(void)
> > #endif
> > }
> >
> > -const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
> > +const __initconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
> > .name = "Microsoft Hyper-V",
> > .detect = ms_hyperv_platform,
> > + .type = X86_HYPER_MS_HYPERV,
> > .init.init_platform = ms_hyperv_init_platform,
> > };
> > -EXPORT_SYMBOL(x86_hyper_ms_hyperv);
> > diff --git a/arch/x86/kernel/cpu/vmware.c
> b/arch/x86/kernel/cpu/vmware.c
> > index 4804c1d063c8..8e005329648b 100644
> > --- a/arch/x86/kernel/cpu/vmware.c
> > +++ b/arch/x86/kernel/cpu/vmware.c
> > @@ -205,10 +205,10 @@ static bool __init
> vmware_legacy_x2apic_available(void)
> > (eax & (1 << VMWARE_PORT_CMD_LEGACY_X2APIC)) != 0;
> > }
> >
> > -const __refconst struct hypervisor_x86 x86_hyper_vmware = {
> > +const __initconst struct hypervisor_x86 x86_hyper_vmware = {
> > .name = "VMware",
> > .detect = vmware_platform,
> > + .type = X86_HYPER_VMWARE,
> > .init.init_platform = vmware_platform_setup,
> > .init.x2apic_available = vmware_legacy_x2apic_available,
> > };
> > -EXPORT_SYMBOL(x86_hyper_vmware);
> > diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
> > index 9dca8437c795..a94de09edbed 100644
> > --- a/arch/x86/kernel/kvm.c
> > +++ b/arch/x86/kernel/kvm.c
> > @@ -544,12 +544,12 @@ static uint32_t __init kvm_detect(void)
> > return kvm_cpuid_base();
> > }
> >
> > -const struct hypervisor_x86 x86_hyper_kvm __refconst = {
> > +const __initconst struct hypervisor_x86 x86_hyper_kvm = {
> > .name = "KVM",
> > .detect = kvm_detect,
> > + .type = X86_HYPER_KVM,
> > .init.x2apic_available = kvm_para_available,
> > };
> > -EXPORT_SYMBOL_GPL(x86_hyper_kvm);
> >
> > static __init int activate_jump_labels(void)
> > {
> > diff --git a/arch/x86/xen/enlighten_hvm.c
> b/arch/x86/xen/enlighten_hvm.c
> > index 7b1622089f96..754d5391d9fa 100644
> > --- a/arch/x86/xen/enlighten_hvm.c
> > +++ b/arch/x86/xen/enlighten_hvm.c
> > @@ -226,12 +226,12 @@ static uint32_t __init xen_platform_hvm(void)
> > return xen_cpuid_base();
> > }
> >
> > -const struct hypervisor_x86 x86_hyper_xen_hvm = {
> > +const __initconst struct hypervisor_x86 x86_hyper_xen_hvm = {
> > .name = "Xen HVM",
> > .detect = xen_platform_hvm,
> > + .type = X86_HYPER_XEN_HVM,
> > .init.init_platform = xen_hvm_guest_init,
> > .init.x2apic_available = xen_x2apic_para_available,
> > .init.init_mem_mapping = xen_hvm_init_mem_mapping,
> > .runtime.pin_vcpu = xen_pin_vcpu,
> > };
> > -EXPORT_SYMBOL(x86_hyper_xen_hvm);
> > diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
> > index 69d1a7054ddb..168efb2534c0 100644
> > --- a/arch/x86/xen/enlighten_pv.c
> > +++ b/arch/x86/xen/enlighten_pv.c
> > @@ -1460,9 +1460,9 @@ static uint32_t __init xen_platform_pv(void)
> > return 0;
> > }
> >
> > -const struct hypervisor_x86 x86_hyper_xen_pv = {
> > +const __initconst struct hypervisor_x86 x86_hyper_xen_pv = {
> > .name = "Xen PV",
> > .detect = xen_platform_pv,
> > + .type = X86_HYPER_XEN_PV,
> > .runtime.pin_vcpu = xen_pin_vcpu,
> > };
> > -EXPORT_SYMBOL(x86_hyper_xen_pv);
> > diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
> > index 937801ac2fe0..2cd134dd94d2 100644
> > --- a/drivers/hv/vmbus_drv.c
> > +++ b/drivers/hv/vmbus_drv.c
> > @@ -1534,7 +1534,7 @@ static int __init hv_acpi_init(void)
> > {
> > int ret, t;
> >
> > - if (x86_hyper != &x86_hyper_ms_hyperv)
> > + if (x86_hyper_type != X86_HYPER_MS_HYPERV)
> > return -ENODEV;
> >
> > init_completion(&probe_event);
> > diff --git a/drivers/input/mouse/vmmouse.c
> b/drivers/input/mouse/vmmouse.c
> > index 0f586780ceb4..1ae5c1ef3f5b 100644
> > --- a/drivers/input/mouse/vmmouse.c
> > +++ b/drivers/input/mouse/vmmouse.c
> > @@ -316,11 +316,9 @@ static int vmmouse_enable(struct psmouse
> *psmouse)
> > /*
> > * Array of supported hypervisors.
> > */
> > -static const struct hypervisor_x86 *vmmouse_supported_hypervisors[] =
> {
> > - &x86_hyper_vmware,
> > -#ifdef CONFIG_KVM_GUEST
> > - &x86_hyper_kvm,
> > -#endif
> > +static enum x86_hypervisor_type vmmouse_supported_hypervisors[] = {
> > + X86_HYPER_VMWARE,
> > + X86_HYPER_KVM,
> > };
> >
> > /**
> > @@ -331,7 +329,7 @@ static bool vmmouse_check_hypervisor(void)
> > int i;
> >
> > for (i = 0; i < ARRAY_SIZE(vmmouse_supported_hypervisors); i++)
> > - if (vmmouse_supported_hypervisors[i] == x86_hyper)
> > + if (vmmouse_supported_hypervisors[i] == x86_hyper_type)
> > return true;
> >
> > return false;
> > diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c
> > index 1e688bfec567..9047c0a529b2 100644
> > --- a/drivers/misc/vmw_balloon.c
> > +++ b/drivers/misc/vmw_balloon.c
> > @@ -1271,7 +1271,7 @@ static int __init vmballoon_init(void)
> > * Check if we are running on VMware's hypervisor and bail out
> > * if we are not.
> > */
> > - if (x86_hyper != &x86_hyper_vmware)
> > + if (x86_hyper_type != X86_HYPER_VMWARE)
> > return -ENODEV;
> >
> > for (is_2m_pages = 0; is_2m_pages <
> VMW_BALLOON_NUM_PAGE_SIZES;
> > --
> > 2.12.3
> >
>
> --
> Dmitry