diff options
Diffstat (limited to 'drivers/lguest/lguest_user.c')
| -rw-r--r-- | drivers/lguest/lguest_user.c | 23 |
1 files changed, 13 insertions, 10 deletions
diff --git a/drivers/lguest/lguest_user.c b/drivers/lguest/lguest_user.c index 80d1b58c769..816d4d12a80 100644 --- a/drivers/lguest/lguest_user.c +++ b/drivers/lguest/lguest_user.c @@ -1,9 +1,9 @@ /*P:200 This contains all the /dev/lguest code, whereby the userspace launcher * controls and communicates with the Guest. For example, the first write will - * tell us the memory size, pagetable, entry point and kernel address offset. - * A read will run the Guest until a signal is pending (-EINTR), or the Guest - * does a DMA out to the Launcher. Writes are also used to get a DMA buffer - * registered by the Guest and to send the Guest an interrupt. :*/ + * tell us the Guest's memory layout, pagetable, entry point and kernel address + * offset. A read will run the Guest until something happens, such as a signal + * or the Guest doing a DMA out to the Launcher. Writes are also used to get a + * DMA buffer registered by the Guest and to send the Guest an interrupt. :*/ #include <linux/uaccess.h> #include <linux/miscdevice.h> #include <linux/fs.h> @@ -142,9 +142,11 @@ static ssize_t read(struct file *file, char __user *user, size_t size,loff_t*o) return run_guest(lg, (unsigned long __user *)user); } -/*L:020 The initialization write supplies 4 32-bit values (in addition to the +/*L:020 The initialization write supplies 5 32-bit values (in addition to the * 32-bit LHREQ_INITIALIZE value). These are: * + * base: The start of the Guest-physical memory inside the Launcher memory. + * * pfnlimit: The highest (Guest-physical) page number the Guest should be * allowed to access. The Launcher has to live in Guest memory, so it sets * this to ensure the Guest can't reach it. @@ -166,7 +168,7 @@ static int initialize(struct file *file, const u32 __user *input) * Guest. */ struct lguest *lg; int err, i; - u32 args[4]; + u32 args[5]; /* We grab the Big Lguest lock, which protects the global array * "lguests" and multiple simultaneous initializations. */ @@ -194,8 +196,9 @@ static int initialize(struct file *file, const u32 __user *input) /* Populate the easy fields of our "struct lguest" */ lg->guestid = i; - lg->pfn_limit = args[0]; - lg->page_offset = args[3]; + lg->mem_base = (void __user *)(long)args[0]; + lg->pfn_limit = args[1]; + lg->page_offset = args[4]; /* We need a complete page for the Guest registers: they are accessible * to the Guest and we can only grant it access to whole pages. */ @@ -210,13 +213,13 @@ static int initialize(struct file *file, const u32 __user *input) /* Initialize the Guest's shadow page tables, using the toplevel * address the Launcher gave us. This allocates memory, so can * fail. */ - err = init_guest_pagetable(lg, args[1]); + err = init_guest_pagetable(lg, args[2]); if (err) goto free_regs; /* Now we initialize the Guest's registers, handing it the start * address. */ - setup_regs(lg->regs, args[2]); + setup_regs(lg->regs, args[3]); /* There are a couple of GDT entries the Guest expects when first * booting. */ |