Re: [PATCH v5 06/16] x86/hyperv: allocate output arg pages if required
On Wed, Jan 20, 2021 at 7:01 AM Wei Liu wrote:
>
> When Linux runs as the root partition, it will need to make hypercalls
> which return data from the hypervisor.
>
> Allocate pages for storing results when Linux runs as the root
> partition.
>
> Signed-off-by: Lillian Grassin-Drake
> Co-Developed-by: Lillian Grassin-Drake
> Signed-off-by: Wei Liu
Reviewed-by: Pavel Tatashin
The new warnings reported by the robot are the same as for the input argument.
Pasha
> ---
> v3: Fix hv_cpu_die to use free_pages.
> v2: Address Vitaly's comments
> ---
> arch/x86/hyperv/hv_init.c | 35 -
> arch/x86/include/asm/mshyperv.h | 1 +
> 2 files changed, 31 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
> index e04d90af4c27..6f4cb40e53fe 100644
> --- a/arch/x86/hyperv/hv_init.c
> +++ b/arch/x86/hyperv/hv_init.c
> @@ -41,6 +41,9 @@ EXPORT_SYMBOL_GPL(hv_vp_assist_page);
> void __percpu **hyperv_pcpu_input_arg;
> EXPORT_SYMBOL_GPL(hyperv_pcpu_input_arg);
>
> +void __percpu **hyperv_pcpu_output_arg;
> +EXPORT_SYMBOL_GPL(hyperv_pcpu_output_arg);
> +
> u32 hv_max_vp_index;
> EXPORT_SYMBOL_GPL(hv_max_vp_index);
>
> @@ -73,12 +76,19 @@ static int hv_cpu_init(unsigned int cpu)
> void **input_arg;
> struct page *pg;
>
> - input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
> /* hv_cpu_init() can be called with IRQs disabled from hv_resume() */
> - pg = alloc_page(irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL);
> + pg = alloc_pages(irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL,
> hv_root_partition ? 1 : 0);
> if (unlikely(!pg))
> return -ENOMEM;
> +
> + input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
> *input_arg = page_address(pg);
> + if (hv_root_partition) {
> + void **output_arg;
> +
> + output_arg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg);
> + *output_arg = page_address(pg + 1);
> + }
>
> hv_get_vp_index(msr_vp_index);
>
> @@ -205,14 +215,23 @@ static int hv_cpu_die(unsigned int cpu)
> unsigned int new_cpu;
> unsigned long flags;
> void **input_arg;
> - void *input_pg = NULL;
> + void *pg;
>
> local_irq_save(flags);
> input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
> - input_pg = *input_arg;
> + pg = *input_arg;
> *input_arg = NULL;
> +
> + if (hv_root_partition) {
> + void **output_arg;
> +
> + output_arg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg);
> + *output_arg = NULL;
> + }
> +
> local_irq_restore(flags);
> - free_page((unsigned long)input_pg);
> +
> + free_pages((unsigned long)pg, hv_root_partition ? 1 : 0);
>
> if (hv_vp_assist_page && hv_vp_assist_page[cpu])
> wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, 0);
> @@ -346,6 +365,12 @@ void __init hyperv_init(void)
>
> BUG_ON(hyperv_pcpu_input_arg == NULL);
>
> + /* Allocate the per-CPU state for output arg for root */
> + if (hv_root_partition) {
> + hyperv_pcpu_output_arg = alloc_percpu(void *);
> + BUG_ON(hyperv_pcpu_output_arg == NULL);
> + }
> +
> /* Allocate percpu VP index */
> hv_vp_index = kmalloc_array(num_possible_cpus(), sizeof(*hv_vp_index),
> GFP_KERNEL);
> diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
> index ac2b0d110f03..62d9390f1ddf 100644
> --- a/arch/x86/include/asm/mshyperv.h
> +++ b/arch/x86/include/asm/mshyperv.h
> @@ -76,6 +76,7 @@ static inline void hv_disable_stimer0_percpu_irq(int irq) {}
> #if IS_ENABLED(CONFIG_HYPERV)
> extern void *hv_hypercall_pg;
> extern void __percpu **hyperv_pcpu_input_arg;
> +extern void __percpu **hyperv_pcpu_output_arg;
>
> static inline u64 hv_do_hypercall(u64 control, void *input, void *output)
> {
> --
> 2.20.1
>
___
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Re: [PATCH v5 02/16] x86/hyperv: detect if Linux is the root partition
On Wed, Jan 20, 2021 at 7:01 AM Wei Liu wrote:
>
> For now we can use the privilege flag to check. Stash the value to be
> used later.
>
> Put in a bunch of defines for future use when we want to have more
> fine-grained detection.
>
> Signed-off-by: Wei Liu
> ---
> v3: move hv_root_partition to mshyperv.c
> ---
> arch/x86/include/asm/hyperv-tlfs.h | 10 ++
> arch/x86/include/asm/mshyperv.h| 2 ++
> arch/x86/kernel/cpu/mshyperv.c | 20
> 3 files changed, 32 insertions(+)
>
> diff --git a/arch/x86/include/asm/hyperv-tlfs.h
> b/arch/x86/include/asm/hyperv-tlfs.h
> index 6bf42aed387e..204010350604 100644
> --- a/arch/x86/include/asm/hyperv-tlfs.h
> +++ b/arch/x86/include/asm/hyperv-tlfs.h
> @@ -21,6 +21,7 @@
> #define HYPERV_CPUID_FEATURES 0x4003
> #define HYPERV_CPUID_ENLIGHTMENT_INFO 0x4004
> #define HYPERV_CPUID_IMPLEMENT_LIMITS 0x4005
> +#define HYPERV_CPUID_CPU_MANAGEMENT_FEATURES 0x4007
> #define HYPERV_CPUID_NESTED_FEATURES 0x400A
>
> #define HYPERV_CPUID_VIRT_STACK_INTERFACE 0x4081
> @@ -110,6 +111,15 @@
> /* Recommend using enlightened VMCS */
> #define HV_X64_ENLIGHTENED_VMCS_RECOMMENDEDBIT(14)
>
> +/*
> + * CPU management features identification.
> + * These are HYPERV_CPUID_CPU_MANAGEMENT_FEATURES.EAX bits.
> + */
> +#define HV_X64_START_LOGICAL_PROCESSOR BIT(0)
> +#define HV_X64_CREATE_ROOT_VIRTUAL_PROCESSOR BIT(1)
> +#define HV_X64_PERFORMANCE_COUNTER_SYNCBIT(2)
> +#define HV_X64_RESERVED_IDENTITY_BIT BIT(31)
> +
> /*
> * Virtual processor will never share a physical core with another virtual
> * processor, except for virtual processors that are reported as sibling SMT
> diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
> index ffc289992d1b..ac2b0d110f03 100644
> --- a/arch/x86/include/asm/mshyperv.h
> +++ b/arch/x86/include/asm/mshyperv.h
> @@ -237,6 +237,8 @@ int hyperv_fill_flush_guest_mapping_list(
> struct hv_guest_mapping_flush_list *flush,
> u64 start_gfn, u64 end_gfn);
>
> +extern bool hv_root_partition;
> +
> #ifdef CONFIG_X86_64
> void hv_apic_init(void);
> void __init hv_init_spinlocks(void);
> diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
> index f628e3dc150f..c376d191a260 100644
> --- a/arch/x86/kernel/cpu/mshyperv.c
> +++ b/arch/x86/kernel/cpu/mshyperv.c
> @@ -32,6 +32,10 @@
> #include
> #include
>
> +/* Is Linux running as the root partition? */
> +bool hv_root_partition;
> +EXPORT_SYMBOL_GPL(hv_root_partition);
> +
> struct ms_hyperv_info ms_hyperv;
> EXPORT_SYMBOL_GPL(ms_hyperv);
>
> @@ -237,6 +241,22 @@ static void __init ms_hyperv_init_platform(void)
> pr_debug("Hyper-V: max %u virtual processors, %u logical
> processors\n",
> ms_hyperv.max_vp_index, ms_hyperv.max_lp_index);
>
> + /*
> +* Check CPU management privilege.
> +*
> +* To mirror what Windows does we should extract CPU management
> +* features and use the ReservedIdentityBit to detect if Linux is the
> +* root partition. But that requires negotiating CPU management
> +* interface (a process to be finalized).
Is this comment relevant? Do we have to mirror what Windows does?
> +*
> +* For now, use the privilege flag as the indicator for running as
> +* root.
> +*/
> + if (cpuid_ebx(HYPERV_CPUID_FEATURES) & HV_CPU_MANAGEMENT) {
> + hv_root_partition = true;
> + pr_info("Hyper-V: running as root partition\n");
> + }
> +
Reviewed-by: Pavel Tatashin
> /*
> * Extract host information.
> */
> --
> 2.20.1
>
___
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Re: [PATCH v5 01/16] asm-generic/hyperv: change HV_CPU_POWER_MANAGEMENT to HV_CPU_MANAGEMENT
On Wed, Jan 20, 2021 at 7:01 AM Wei Liu wrote: > > This makes the name match Hyper-V TLFS. > > Signed-off-by: Wei Liu > Reviewed-by: Vitaly Kuznetsov > --- > include/asm-generic/hyperv-tlfs.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/asm-generic/hyperv-tlfs.h > b/include/asm-generic/hyperv-tlfs.h > index e73a11850055..e6903589a82a 100644 > --- a/include/asm-generic/hyperv-tlfs.h > +++ b/include/asm-generic/hyperv-tlfs.h > @@ -88,7 +88,7 @@ > #define HV_CONNECT_PORTBIT(7) > #define HV_ACCESS_STATSBIT(8) > #define HV_DEBUGGING BIT(11) > -#define HV_CPU_POWER_MANAGEMENTBIT(12) > +#define HV_CPU_MANAGEMENT BIT(12) Reviewed-by: Pavel Tatashin ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Re: [PATCH v5 05/16] clocksource/hyperv: use MSR-based access if running as root
On Wed, Jan 20, 2021 at 7:01 AM Wei Liu wrote: > > When Linux runs as the root partition, the setup required for TSC page > is different. Why would we need a TSC page as a clock source for root partition at all? I think the above can be removed. Luckily Linux also has access to the MSR based > clocksource. We can just disable the TSC page clocksource if Linux is > the root partition. > > Signed-off-by: Wei Liu > Acked-by: Daniel Lezcano > --- > drivers/clocksource/hyperv_timer.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/clocksource/hyperv_timer.c > b/drivers/clocksource/hyperv_timer.c > index ba04cb381cd3..269a691bd2c4 100644 > --- a/drivers/clocksource/hyperv_timer.c > +++ b/drivers/clocksource/hyperv_timer.c > @@ -426,6 +426,9 @@ static bool __init hv_init_tsc_clocksource(void) > if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE)) > return false; > > + if (hv_root_partition) > + return false; > + Reviewed-by: Pavel Tatashin ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Re: [PATCH v5 04/16] iommu/hyperv: don't setup IRQ remapping when running as root
On Wed, Jan 20, 2021 at 7:01 AM Wei Liu wrote: > > The IOMMU code needs more work. We're sure for now the IRQ remapping > hooks are not applicable when Linux is the root partition. > > Signed-off-by: Wei Liu > Acked-by: Joerg Roedel > Reviewed-by: Vitaly Kuznetsov > --- > drivers/iommu/hyperv-iommu.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/hyperv-iommu.c b/drivers/iommu/hyperv-iommu.c > index 1d21a0b5f724..b7db6024e65c 100644 > --- a/drivers/iommu/hyperv-iommu.c > +++ b/drivers/iommu/hyperv-iommu.c > @@ -20,6 +20,7 @@ > #include > #include > #include > +#include > > #include "irq_remapping.h" > > @@ -122,7 +123,7 @@ static int __init hyperv_prepare_irq_remapping(void) > > if (!hypervisor_is_type(X86_HYPER_MS_HYPERV) || > x86_init.hyper.msi_ext_dest_id() || > - !x2apic_supported()) > + !x2apic_supported() || hv_root_partition) > return -ENODEV; Reviewed-by: Pavel Tatashin ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Re: [PATCH v5 03/16] Drivers: hv: vmbus: skip VMBus initialization if Linux is root
On Wed, Jan 20, 2021 at 7:01 AM Wei Liu wrote: > > There is no VMBus and the other infrastructures initialized in > hv_acpi_init when Linux is running as the root partition. > > Signed-off-by: Wei Liu > --- > v3: Return 0 instead of -ENODEV. > --- > drivers/hv/vmbus_drv.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c > index 502f8cd95f6d..ee27b3670a51 100644 > --- a/drivers/hv/vmbus_drv.c > +++ b/drivers/hv/vmbus_drv.c > @@ -2620,6 +2620,9 @@ static int __init hv_acpi_init(void) > if (!hv_is_hyperv_initialized()) > return -ENODEV; > > + if (hv_root_partition) > + return 0; > + Reviewed-by: Pavel Tatashin ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
