Re: [Xen-devel] [PATCH 02/12] early PV on HVM

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Thu, Jun 03, 2010 at 02:10:35PM +0100, stefano.stabellini@eu.citrix.com wrote:
> From: Sheng Yang <sheng@linux.intel.com>
> 
> Initialize basic pv on hvm features in xen_guest_init.
> 
> The hook in arch/x86/kernel/setup.c can easily be removed using the new
> generic hypervisor independent initialization infrastructure present in
> the linux-2.6-tip tree.
> 
> 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>
> ---
>  arch/x86/kernel/setup.c           |    2 +
>  arch/x86/xen/enlighten.c          |   86 +++++++++++++++++++++++++++++++++++++
>  drivers/input/xen-kbdfront.c      |    2 +-
>  drivers/video/xen-fbfront.c       |    2 +-
>  drivers/xen/xenbus/xenbus_probe.c |   21 ++++++++-
>  include/xen/xen.h                 |    2 +
>  6 files changed, 110 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index c4851ef..ae9b6cb 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -69,6 +69,7 @@
>  #include <linux/tboot.h>
>  
>  #include <video/edid.h>
> +#include <xen/xen.h>
>  
>  #include <asm/mtrr.h>
>  #include <asm/apic.h>
> @@ -1032,6 +1033,7 @@ 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 65d8d79..c1f6545 100644
> --- a/arch/x86/xen/enlighten.c
> +++ b/arch/x86/xen/enlighten.c
> @@ -35,6 +35,7 @@
>  #include <xen/interface/version.h>
>  #include <xen/interface/physdev.h>
>  #include <xen/interface/vcpu.h>
> +#include <xen/interface/memory.h>
>  #include <xen/features.h>
>  #include <xen/page.h>
>  #include <xen/hvc-console.h>
> @@ -56,6 +57,7 @@
>  #include <asm/tlbflush.h>
>  #include <asm/reboot.h>
>  #include <asm/stackprotector.h>
> +#include <asm/hypervisor.h>
>  
>  #include "xen-ops.h"
>  #include "mmu.h"
> @@ -1206,3 +1208,87 @@ 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(int *major, int *minor)
> +{
> +	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);
> +
> +	*major = eax >> 16;
> +	*minor = eax & 0xffff;
> +	printk(KERN_INFO "Xen version %d.%d.\n", *major, *minor);
> +
> +	cpuid(base + 2, &pages, &msr, &ecx, &edx);
> +
> +	pfn = __pa(hypercall_page);
> +	wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
> +
> +	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. */

Might want to mention where the full vpcu placement is done.
> +	per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];

Otherwise looks good to me. In other words, Reviewed-by: Konrad
Rzeszutek Wilk <konrad.wilk@oracle.com>