Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus (a7e1aabb) · Commits · e / devices / android_kernel_xiaomi_markw

Documentation/virtual/lguest/lguest.c

+16 −31

Original line number	Diff line number	Diff line
		@@ -51,7 +51,7 @@
		#include <asm/bootparam.h>
		#include "../../../include/linux/lguest_launcher.h"
		/*L:110
		* We can ignore the 42 include files we need for this program, but I do want
		* We can ignore the 43 include files we need for this program, but I do want
		* to draw attention to the use of kernel-style types.
		*
		* As Linus said, "C is a Spartan language, and so should your naming be." I
		@@ -65,7 +65,6 @@ typedef uint16_t u16;
		typedef uint8_t u8;
		/:/

		#define PAGE_PRESENT 0x7 /* Present, RW, Execute */
		#define BRIDGE_PFX "bridge:"
		#ifndef SIOCBRADDIF
		#define SIOCBRADDIF 0x89a2 /* add interface to bridge */
		@@ -861,8 +860,10 @@ static void console_output(struct virtqueue *vq)
		/* writev can return a partial write, so we loop here. */
		while (!iov_empty(iov, out)) {
		int len = writev(STDOUT_FILENO, iov, out);
		if (len <= 0)
		err(1, "Write to stdout gave %i", len);
		if (len <= 0) {
		warn("Write to stdout gave %i (%d)", len, errno);
		break;
		}
		iov_consume(iov, out, len);
		}

		@@ -898,7 +899,7 @@ static void net_output(struct virtqueue *vq)
		* same format: what a coincidence!
		*/
		if (writev(net_info->tunfd, iov, out) < 0)
		errx(1, "Write to tun failed?");
		warnx("Write to tun failed (%d)?", errno);

		/*
		* Done with that one; wait_for_vq_desc() will send the interrupt if
		@@ -955,7 +956,7 @@ static void net_input(struct virtqueue *vq)
		*/
		len = readv(net_info->tunfd, iov, in);
		if (len <= 0)
		err(1, "Failed to read from tun.");
		warn("Failed to read from tun (%d).", errno);

		/*
		* Mark that packet buffer as used, but don't interrupt here. We want
		@@ -1093,8 +1094,9 @@ static void update_device_status(struct device *dev)
		warnx("Device %s configuration FAILED", dev->name);
		if (dev->running)
		reset_device(dev);
		} else if (dev->desc->status & VIRTIO_CONFIG_S_DRIVER_OK) {
		if (!dev->running)
		} else {
		if (dev->running)
		err(1, "Device %s features finalized twice", dev->name);
		start_device(dev);
		}
		}
		@@ -1120,25 +1122,11 @@ static void handle_output(unsigned long addr)
		return;
		}

		/*
		* Devices can be used before status is set to DRIVER_OK.
		* The original plan was that they would never do this: they
		* would always finish setting up their status bits before
		* actually touching the virtqueues. In practice, we allowed
		* them to, and they do (eg. the disk probes for partition
		* tables as part of initialization).
		*
		* If we see this, we start the device: once it's running, we
		* expect the device to catch all the notifications.
		*/
		/* Devices should not be used before features are finalized. */
		for (vq = i->vq; vq; vq = vq->next) {
		if (addr != vq->config.pfn*getpagesize())
		continue;
		if (i->running)
		errx(1, "Notification on running %s", i->name);
		/* This just calls create_thread() for each virtqueue */
		start_device(i);
		return;
		errx(1, "Notification on %s before setup!", i->name);
		}
		}

		@@ -1370,7 +1358,7 @@ static void setup_console(void)
		* --sharenet=<name> option which opens or creates a named pipe. This can be
		* used to send packets to another guest in a 1:1 manner.
		*
		* More sopisticated is to use one of the tools developed for project like UML
		* More sophisticated is to use one of the tools developed for project like UML
		* to do networking.
		*
		* Faster is to do virtio bonding in kernel. Doing this 1:1 would be
		@@ -1380,7 +1368,7 @@ static void setup_console(void)
		* multiple inter-guest channels behind one interface, although it would
		* require some manner of hotplugging new virtio channels.
		*
		* Finally, we could implement a virtio network switch in the kernel.
		* Finally, we could use a virtio network switch in the kernel, ie. vhost.
		:*/

		static u32 str2ip(const char *ipaddr)
		@@ -2017,10 +2005,7 @@ int main(int argc, char *argv[])
		/* Tell the entry path not to try to reload segment registers. */
		boot->hdr.loadflags \|= KEEP_SEGMENTS;

		/*
		* We tell the kernel to initialize the Guest: this returns the open
		* /dev/lguest file descriptor.
		*/
		/* We tell the kernel to initialize the Guest. */
		tell_kernel(start);

		/* Ensure that we terminate if a device-servicing child dies. */

arch/x86/include/asm/lguest_hcall.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -61,6 +61,7 @@ hcall(unsigned long call,
		: "memory");
		return call;
		}
		/:/

		/* Can't use our min() macro here: needs to be a constant */
		#define LGUEST_IRQS (NR_IRQS < 32 ? NR_IRQS: 32)

arch/x86/kernel/asm-offsets_32.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -63,7 +63,6 @@ void foo(void)
		BLANK();
		OFFSET(LGUEST_DATA_irq_enabled, lguest_data, irq_enabled);
		OFFSET(LGUEST_DATA_irq_pending, lguest_data, irq_pending);
		OFFSET(LGUEST_DATA_pgdir, lguest_data, pgdir);

		BLANK();
		OFFSET(LGUEST_PAGES_host_gdt_desc, lguest_pages, state.host_gdt_desc);

arch/x86/lguest/boot.c

+22 −14

Original line number	Diff line number	Diff line
		@@ -71,7 +71,8 @@
		#include <asm/stackprotector.h>
		#include <asm/reboot.h> /* for struct machine_ops */

		/*G:010 Welcome to the Guest!
		/*G:010
		* Welcome to the Guest!
		*
		* The Guest in our tale is a simple creature: identical to the Host but
		* behaving in simplified but equivalent ways. In particular, the Guest is the
		@@ -190,15 +191,23 @@ static void lazy_hcall4(unsigned long call,
		#endif

		/*G:036
		* When lazy mode is turned off reset the per-cpu lazy mode variable and then
		* issue the do-nothing hypercall to flush any stored calls.
		:*/
		* When lazy mode is turned off, we issue the do-nothing hypercall to
		* flush any stored calls, and call the generic helper to reset the
		* per-cpu lazy mode variable.
		*/
		static void lguest_leave_lazy_mmu_mode(void)
		{
		hcall(LHCALL_FLUSH_ASYNC, 0, 0, 0, 0);
		paravirt_leave_lazy_mmu();
		}

		/*
		* We also catch the end of context switch; we enter lazy mode for much of
		* that too, so again we need to flush here.
		*
		* (Technically, this is lazy CPU mode, and normally we're in lazy MMU
		* mode, but unlike Xen, lguest doesn't care about the difference).
		*/
		static void lguest_end_context_switch(struct task_struct *next)
		{
		hcall(LHCALL_FLUSH_ASYNC, 0, 0, 0, 0);
		@@ -391,7 +400,7 @@ static void lguest_load_tr_desc(void)
		* giant ball of hair. Its entry in the current Intel manual runs to 28 pages.
		*
		* This instruction even it has its own Wikipedia entry. The Wikipedia entry
		* has been translated into 5 languages. I am not making this up!
		* has been translated into 6 languages. I am not making this up!
		*
		* We could get funky here and identify ourselves as "GenuineLguest", but
		* instead we just use the real "cpuid" instruction. Then I pretty much turned
		@@ -458,7 +467,7 @@ static void lguest_cpuid(unsigned int ax, unsigned int bx,
		/*
		* PAE systems can mark pages as non-executable. Linux calls this the
		* NX bit. Intel calls it XD (eXecute Disable), AMD EVP (Enhanced
		* Virus Protection). We just switch turn if off here, since we don't
		* Virus Protection). We just switch it off here, since we don't
		* support it.
		*/
		case 0x80000001:
		@@ -520,17 +529,16 @@ static unsigned long lguest_read_cr2(void)

		/* See lguest_set_pte() below. */
		static bool cr3_changed = false;
		static unsigned long current_cr3;

		/*
		* cr3 is the current toplevel pagetable page: the principle is the same as
		* cr0. Keep a local copy, and tell the Host when it changes. The only
		* difference is that our local copy is in lguest_data because the Host needs
		* to set it upon our initial hypercall.
		* cr0. Keep a local copy, and tell the Host when it changes.
		*/
		static void lguest_write_cr3(unsigned long cr3)
		{
		lguest_data.pgdir = cr3;
		lazy_hcall1(LHCALL_NEW_PGTABLE, cr3);
		current_cr3 = cr3;

		/* These two page tables are simple, linear, and used during boot */
		if (cr3 != __pa(swapper_pg_dir) && cr3 != __pa(initial_page_table))
		@@ -539,7 +547,7 @@ static void lguest_write_cr3(unsigned long cr3)

		static unsigned long lguest_read_cr3(void)
		{
		return lguest_data.pgdir;
		return current_cr3;
		}

		/* cr4 is used to enable and disable PGE, but we don't care. */
		@@ -758,7 +766,7 @@ static void lguest_pmd_clear(pmd_t *pmdp)
		static void lguest_flush_tlb_single(unsigned long addr)
		{
		/* Simply set it to zero: if it was not, it will fault back in. */
		lazy_hcall3(LHCALL_SET_PTE, lguest_data.pgdir, addr, 0);
		lazy_hcall3(LHCALL_SET_PTE, current_cr3, addr, 0);
		}

		/*

arch/x86/lguest/i386_head.S

+20 −15

Original line number	Diff line number	Diff line
		@@ -6,18 +6,22 @@
		#include <asm/processor-flags.h>

		/*G:020
		* Our story starts with the kernel booting into startup_32 in
		* arch/x86/kernel/head_32.S. It expects a boot header, which is created by
		* the bootloader (the Launcher in our case).

		* Our story starts with the bzImage: booting starts at startup_32 in
		* arch/x86/boot/compressed/head_32.S. This merely uncompresses the real
		* kernel in place and then jumps into it: startup_32 in
		* arch/x86/kernel/head_32.S. Both routines expects a boot header in the %esi
		* register, which is created by the bootloader (the Launcher in our case).
		*
		* The startup_32 function does very little: it clears the uninitialized global
		* C variables which we expect to be zero (ie. BSS) and then copies the boot
		* header and kernel command line somewhere safe. Finally it checks the
		* 'hardware_subarch' field. This was introduced in 2.6.24 for lguest and Xen:
		* if it's set to '1' (lguest's assigned number), then it calls us here.
		* header and kernel command line somewhere safe, and populates some initial
		* page tables. Finally it checks the 'hardware_subarch' field. This was
		* introduced in 2.6.24 for lguest and Xen: if it's set to '1' (lguest's
		* assigned number), then it calls us here.
		*
		* WARNING: be very careful here! We're running at addresses equal to physical
		* addesses (around 0), not above PAGE_OFFSET as most code expectes
		* addresses (around 0), not above PAGE_OFFSET as most code expects
		* (eg. 0xC0000000). Jumps are relative, so they're OK, but we can't touch any
		* data without remembering to subtract __PAGE_OFFSET!
		*
		@@ -27,13 +31,18 @@
		.section .init.text, "ax", @progbits
		ENTRY(lguest_entry)
		/*
		* We make the "initialization" hypercall now to tell the Host about
		* us, and also find out where it put our page tables.
		* We make the "initialization" hypercall now to tell the Host where
		* our lguest_data struct is.
		*/
		movl $LHCALL_LGUEST_INIT, %eax
		movl $lguest_data - __PAGE_OFFSET, %ebx
		int $LGUEST_TRAP_ENTRY

		/* Now turn our pagetables on; setup by arch/x86/kernel/head_32.S. */
		movl $LHCALL_NEW_PGTABLE, %eax
		movl $(initial_page_table - __PAGE_OFFSET), %ebx
		int $LGUEST_TRAP_ENTRY

		/* Set up the initial stack so we can run C code. */
		movl $(init_thread_union+THREAD_SIZE),%esp

		@@ -96,12 +105,8 @@ send_interrupts:
		*/
		pushl %eax
		movl $LHCALL_SEND_INTERRUPTS, %eax
		/*
		* This is a vmcall instruction (same thing that KVM uses). Older
		* assembler versions might not know the "vmcall" instruction, so we
		* create one manually here.
		*/
		.byte 0x0f,0x01,0xc1 /* KVM_HYPERCALL */
		/* This is the actual hypercall trap. */
		int $LGUEST_TRAP_ENTRY
		/* Put eax back the way we found it. */
		popl %eax
		ret