Re: [Xen-devel] [PATCH 2 of 5] early PV on HVM

[Jeremy Fitzhardinge <jeremy@goop.org>]

On 03/10/2010 07:47 AM, Stefano Stabellini wrote:
> Hi all,
> this patch:
>
> - adds a xen_guest_init hook in setup.c right after kvm_guest_init;
>
> - initializes basic pv on hvm features in xen_guest_init;
>    

Is this 64-bit specific like Sheng's version?

I also asked him to move the setup code out of enlighten.c into a new 
file, though your version is a fair bit smaller.

> Signed-off-by: Stefano Stabellini<stefano.stabellini@eu.citrix.com>
> Signed-off-by: Sheng Yang<sheng@linux.intel.com>
> Signed-off-by: Yaozu (Eddie) Dong<eddie.dong@intel.com>
>
> ---
>
> diff --git a/arch/x86/include/asm/xen/hypervisor.h b/arch/x86/include/asm/xen/hypervisor.h
> index d5b7e90..bbd3f65 100644
> --- a/arch/x86/include/asm/xen/hypervisor.h
> +++ b/arch/x86/include/asm/xen/hypervisor.h
> @@ -33,6 +33,7 @@
>   #ifndef _ASM_X86_XEN_HYPERVISOR_H
>   #define _ASM_X86_XEN_HYPERVISOR_H
>
> +#ifdef CONFIG_XEN
>   /* arch/i386/kernel/setup.c */
>   extern struct shared_info *HYPERVISOR_shared_info;
>   extern struct start_info *xen_start_info;
> @@ -43,10 +44,11 @@ enum xen_domain_type {
>   	XEN_HVM_DOMAIN,		/* running in a Xen hvm domain */
>   };
>
> -#ifdef CONFIG_XEN
>   extern enum xen_domain_type xen_domain_type;
> +extern void xen_guest_init(void);
>   #else
>   #define xen_domain_type		XEN_NATIVE
> +#define xen_guest_init() do { } while (0)
>   #endif
>
>   #define xen_domain()		(xen_domain_type != XEN_NATIVE)
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index e09f0e2..cb32e37 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -49,6 +49,7 @@
>   #include<asm/pci-direct.h>
>   #include<linux/init_ohci1394_dma.h>
>   #include<linux/kvm_para.h>
> +#include<asm/xen/hypervisor.h>
>
>   #include<linux/errno.h>
>   #include<linux/kernel.h>
> @@ -1007,6 +1008,7 @@ void __init setup_arch(char **cmdline_p)
>   	probe_nr_irqs_gsi();
>
>   	kvm_guest_init();
> +	xen_guest_init();
>
>   	e820_reserve_resources();
>   	e820_mark_nosave_regions(max_low_pfn);
> diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
> index 3439616..42135e8 100644
> --- a/arch/x86/xen/enlighten.c
> +++ b/arch/x86/xen/enlighten.c
> @@ -32,6 +32,8 @@
>   #include<xen/interface/version.h>
>   #include<xen/interface/physdev.h>
>   #include<xen/interface/vcpu.h>
> +#include<xen/interface/memory.h>
> +#include<xen/interface/hvm/hvm_op.h>
>   #include<xen/features.h>
>   #include<xen/page.h>
>   #include<xen/hvc-console.h>
> @@ -1179,3 +1181,86 @@ asmlinkage void __init xen_start_kernel(void)
>   	x86_64_start_reservations((char *)__pa_symbol(&boot_params));
>   #endif
>   }
> +
> +static uint32_t xen_cpuid_base(void)
> +{
> +	uint32_t base, eax, ebx, ecx, edx;
> +	char signature[13];
> +
> +	for (base = 0x40000000; base<  0x40010000; base += 0x100) {
> +		cpuid(base,&eax,&ebx,&ecx,&edx);
> +		*(uint32_t*)(signature + 0) = ebx;
> +		*(uint32_t*)(signature + 4) = ecx;
> +		*(uint32_t*)(signature + 8) = edx;
> +		signature[12] = 0;
> +
> +		if (!strcmp("XenVMMXenVMM", signature)&&  ((eax - base)>= 2))
> +			return base;
> +	}
> +
> +	return 0;
> +}
> +
> +static int init_hvm_pv_info(void)
> +{
> +	uint32_t eax, ebx, ecx, edx, pages, msr, base;
> +	u64 pfn;
> +
> +	base = xen_cpuid_base();
> +	if (!base)
> +		return -EINVAL;
> +
> +	cpuid(base + 1,&eax,&ebx,&ecx,&edx);
> +
> +	printk(KERN_INFO "Xen version %d.%d.\n", eax>>  16, eax&  0xffff);
> +
> +	cpuid(base + 2,&pages,&msr,&ecx,&edx);
> +
> +	/* We only support 1 page of hypercall for now */
> +	if (pages != 1)
> +		return -ENOMEM;
>    

There's no point testing this; if we don't use hypercalls beyond the 
first page, it doesn't matter one way or the other.

> +
> +	pfn = __pa(hypercall_page);
> +	wrmsrl(msr, pfn);
>    

Use wrmsr_safe, just in case.

> +
> +	xen_setup_features();
> +
> +	pv_info = xen_info;
> +	pv_info.kernel_rpl = 0;
> +
> +	xen_domain_type = XEN_HVM_DOMAIN;
> +
> +	return 0;
> +}
> +
> +static void __init init_shared_info(void)
> +{
> +	struct xen_add_to_physmap xatp;
> +	struct shared_info *shared_info_page;
> +
> +	shared_info_page = (struct shared_info *) alloc_bootmem_pages(PAGE_SIZE);
> +	xatp.domid = DOMID_SELF;
> +	xatp.idx = 0;
> +	xatp.space = XENMAPSPACE_shared_info;
> +	xatp.gpfn = __pa(shared_info_page)>>  PAGE_SHIFT;
> +	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap,&xatp))
> +		BUG();
> +
> +	HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
> +
> +	/* Don't do the full vcpu_info placement stuff until we have a
> +	   possible map and a non-dummy shared_info. */
> +	per_cpu(xen_vcpu, 0) =&HYPERVISOR_shared_info->vcpu_info[0];
> +}
> +
> +void __init xen_guest_init(void)
> +{
> +	int r;
> +
> +	r = init_hvm_pv_info();
> +	if (r<  0)
> +		return;
> +
> +	init_shared_info();
> +}
> +
> diff --git a/drivers/input/xen-kbdfront.c b/drivers/input/xen-kbdfront.c
> index b115726..bfbb13b 100644
> --- a/drivers/input/xen-kbdfront.c
> +++ b/drivers/input/xen-kbdfront.c
> @@ -342,6 +342,9 @@ static int __init xenkbd_init(void)
>   	if (xen_initial_domain())
>   		return -ENODEV;
>
> +	if (xen_hvm_domain())
> +		return -ENODEV;
>    

I think you can combine these into the same if().  Also put it in a 
separate patch.

> +
>   	return xenbus_register_frontend(&xenkbd_driver);
>   }
>
> diff --git a/drivers/video/xen-fbfront.c b/drivers/video/xen-fbfront.c
> index 54cd916..9d74c14 100644
> --- a/drivers/video/xen-fbfront.c
> +++ b/drivers/video/xen-fbfront.c
> @@ -687,6 +687,9 @@ static int __init xenfb_init(void)
>   	if (xen_initial_domain())
>   		return -ENODEV;
>
> +	if (xen_hvm_domain())
> +		return -ENODEV;
>    

Ditto.

> +
>   	return xenbus_register_frontend(&xenfb_driver);
>   }
>
> diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
> index d42e25d..586b8f8 100644
> --- a/drivers/xen/xenbus/xenbus_probe.c
> +++ b/drivers/xen/xenbus/xenbus_probe.c
> @@ -53,6 +53,8 @@
>   #include<xen/events.h>
>   #include<xen/page.h>
>
> +#include<xen/hvm.h>
> +
>   #include "xenbus_comms.h"
>   #include "xenbus_probe.h"
>
> @@ -803,10 +805,19 @@ static int __init xenbus_probe_init(void)
>   		/* dom0 not yet supported */
>   	} else {
>   		xenstored_ready = 1;
> -		xen_store_evtchn = xen_start_info->store_evtchn;
> -		xen_store_mfn = xen_start_info->store_mfn;
> +		if (xen_hvm_domain()) {
> +			xen_store_evtchn =
> +				hvm_get_parameter(HVM_PARAM_STORE_EVTCHN);
> +			xen_store_mfn =
> +				hvm_get_parameter(HVM_PARAM_STORE_PFN);
> +			xen_store_interface =
> +				ioremap(xen_store_mfn<<  PAGE_SHIFT, PAGE_SIZE);
> +		} else {
> +			xen_store_evtchn = xen_start_info->store_evtchn;
> +			xen_store_mfn = xen_start_info->store_mfn;
> +			xen_store_interface = mfn_to_virt(xen_store_mfn);
> +		}
>   	}
> -	xen_store_interface = mfn_to_virt(xen_store_mfn);
>
>   	/* Initialize the interface to xenstore. */
>   	err = xs_init();
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
>
>