Re: [PATCH 18/22] mini-os: map shared info page for HVMlite

[Samuel Thibault <samuel.thibault@ens-lyon.org>]

Juergen Gross, on Tue 23 Aug 2016 17:16:04 +0200, wrote:
> Add a service function to map the shared info page on a
> non-paravirtualized system. The code is already existing on ARM side,
> just move it to hypervisor.c.
> 
> Signed-off-by: Juergen Gross <jgross@suse.com>

Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

> ---
>  arch/arm/arm32.S     |  4 ++--
>  arch/arm/setup.c     | 11 +----------
>  arch/x86/setup.c     | 38 ++++++++++++++++++++------------------
>  hypervisor.c         | 17 +++++++++++++++++
>  include/hypervisor.h |  1 +
>  5 files changed, 41 insertions(+), 30 deletions(-)
> 
> diff --git a/arch/arm/arm32.S b/arch/arm/arm32.S
> index a08a170..bcaca17 100644
> --- a/arch/arm/arm32.S
> +++ b/arch/arm/arm32.S
> @@ -151,8 +151,8 @@ stage2:
>  .pushsection .bss
>  @ Note: calling arch_init zeroes out this region.
>  .align 12
> -.globl shared_info_page
> -shared_info_page:
> +.globl shared_info
> +shared_info:
>  	.fill (1024), 4, 0x0
>  
>  .align 3
> diff --git a/arch/arm/setup.c b/arch/arm/setup.c
> index 72e025a..05b405b 100644
> --- a/arch/arm/setup.c
> +++ b/arch/arm/setup.c
> @@ -21,8 +21,6 @@ union start_info_union start_info_union;
>   */
>  shared_info_t *HYPERVISOR_shared_info;
>  
> -extern char shared_info_page[PAGE_SIZE];
> -
>  void *device_tree;
>  
>  /*
> @@ -30,7 +28,6 @@ void *device_tree;
>   */
>  void arch_init(void *dtb_pointer, uint32_t physical_offset)
>  {
> -    struct xen_add_to_physmap xatp;
>      int r;
>  
>      memset(&__bss_start, 0, &_end - &__bss_start);
> @@ -48,13 +45,7 @@ void arch_init(void *dtb_pointer, uint32_t physical_offset)
>      device_tree = dtb_pointer;
>  
>      /* Map shared_info page */
> -    xatp.domid = DOMID_SELF;
> -    xatp.idx = 0;
> -    xatp.space = XENMAPSPACE_shared_info;
> -    xatp.gpfn = virt_to_pfn(shared_info_page);
> -    if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp) != 0)
> -        BUG();
> -    HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
> +    HYPERVISOR_shared_info = map_shared_info(NULL);
>  
>      /* Fill in start_info */
>      get_console(NULL);
> diff --git a/arch/x86/setup.c b/arch/x86/setup.c
> index 13633f0..278e88f 100644
> --- a/arch/x86/setup.c
> +++ b/arch/x86/setup.c
> @@ -60,20 +60,6 @@ extern char shared_info[PAGE_SIZE];
>      ((pte_t) {(unsigned long)(_x), (unsigned long)(_x>>32)}); })
>  #endif
>  
> -static
> -shared_info_t *map_shared_info(unsigned long pa)
> -{
> -    int rc;
> -
> -	if ( (rc = HYPERVISOR_update_va_mapping(
> -              (unsigned long)shared_info, __pte(pa | 7), UVMF_INVLPG)) )
> -	{
> -		printk("Failed to map shared_info!! rc=%d\n", rc);
> -		do_exit();
> -	}
> -	return (shared_info_t *)shared_info;
> -}
> -
>  static inline void fpu_init(void) {
>  	asm volatile("fninit");
>  }
> @@ -90,6 +76,21 @@ static inline void sse_init(void) {
>  #ifdef CONFIG_PARAVIRT
>  #define hpc_init()
>  
> +shared_info_t *map_shared_info(void *p)
> +{
> +    int rc;
> +    start_info_t *si = p;
> +    unsigned long pa = si->shared_info;
> +
> +    if ( (rc = HYPERVISOR_update_va_mapping((unsigned long)shared_info,
> +                                            __pte(pa | 7), UVMF_INVLPG)) )
> +    {
> +        printk("Failed to map shared_info!! rc=%d\n", rc);
> +        do_exit();
> +    }
> +    return (shared_info_t *)shared_info;
> +}
> +
>  static void get_cmdline(void *p)
>  {
>      start_info_t *si = p;
> @@ -156,6 +157,10 @@ arch_init(void *par)
>  	get_console(par);
>  	get_xenbus(par);
>  	get_cmdline(par);
> +
> +	/* Grab the shared_info pointer and put it in a safe place. */
> +	HYPERVISOR_shared_info = map_shared_info(par);
> +
>  	si = par;
>  	memcpy(&start_info, si, sizeof(*si));
>  
> @@ -163,7 +168,7 @@ arch_init(void *par)
>  	printk("Xen Minimal OS!\n");
>  	printk("  start_info: %p(VA)\n", si);
>  	printk("    nr_pages: 0x%lx\n", si->nr_pages);
> -	printk("  shared_inf: 0x%08lx(MA)\n", si->shared_info);
> +	printk("  shared_inf: %p(VA)\n", HYPERVISOR_shared_info);
>  	printk("     pt_base: %p(VA)\n", (void *)si->pt_base);
>  	printk("nr_pt_frames: 0x%lx\n", si->nr_pt_frames);
>  	printk("    mfn_list: %p(VA)\n", (void *)si->mfn_list);
> @@ -173,9 +178,6 @@ arch_init(void *par)
>  	printk("    cmd_line: %s\n", cmdline);
>  	printk("       stack: %p-%p\n", stack, stack + sizeof(stack));
>  
> -	/* Grab the shared_info pointer and put it in a safe place. */
> -	HYPERVISOR_shared_info = map_shared_info(start_info.shared_info);
> -
>  	start_kernel();
>  }
>  
> diff --git a/hypervisor.c b/hypervisor.c
> index 715cfe8..1647121 100644
> --- a/hypervisor.c
> +++ b/hypervisor.c
> @@ -29,6 +29,7 @@
>  #include <mini-os/lib.h>
>  #include <mini-os/hypervisor.h>
>  #include <mini-os/events.h>
> +#include <xen/memory.h>
>  
>  #define active_evtchns(cpu,sh,idx)              \
>      ((sh)->evtchn_pending[idx] &                \
> @@ -37,6 +38,8 @@
>  int in_callback;
>  
>  #ifndef CONFIG_PARAVIRT
> +extern shared_info_t shared_info;
> +
>  int hvm_get_parameter(int idx, uint64_t *value)
>  {
>      struct xen_hvm_param xhv;
> @@ -61,6 +64,20 @@ int hvm_set_parameter(int idx, uint64_t value)
>      xhv.value = value;
>      return HYPERVISOR_hvm_op(HVMOP_set_param, &xhv);
>  }
> +
> +shared_info_t *map_shared_info(void *p)
> +{
> +    struct xen_add_to_physmap xatp;
> +
> +    xatp.domid = DOMID_SELF;
> +    xatp.idx = 0;
> +    xatp.space = XENMAPSPACE_shared_info;
> +    xatp.gpfn = virt_to_pfn(&shared_info);
> +    if ( HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp) != 0 )
> +        BUG();
> +
> +    return &shared_info;
> +}
>  #endif
>  
>  void do_hypervisor_callback(struct pt_regs *regs)
> diff --git a/include/hypervisor.h b/include/hypervisor.h
> index 6e421b1..7c44702 100644
> --- a/include/hypervisor.h
> +++ b/include/hypervisor.h
> @@ -42,6 +42,7 @@ extern union start_info_union start_info_union;
>  int hvm_get_parameter(int idx, uint64_t *value);
>  int hvm_set_parameter(int idx, uint64_t value);
>  #endif
> +shared_info_t *map_shared_info(void *p);
>  void force_evtchn_callback(void);
>  void do_hypervisor_callback(struct pt_regs *regs);
>  void mask_evtchn(uint32_t port);
> -- 
> 2.6.6
> 

-- 
Samuel
<m> bouhouhouh, b il m'a abandonné. Tout ca parce que je regardais plus mon emacs que lui !
<m> s/lui/ses messages irc/
 -+- #ens-mim esseulé -+-

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