[PATCH 04/16] per-cpu run guest

Glauber de Oliveira Costa
2008-01-07T13:07:01Z

This patch makes the run_guest() routine use the vcpu struct.
This is required since in a smp guest environment, there's no
more the notion of "running the guest", but rather, it is "running the vcpu"

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
---
drivers/lguest/core.c | 6 ++++--
drivers/lguest/lg.h | 4 ++--
drivers/lguest/lguest_user.c | 10 +++++++++-
drivers/lguest/x86/core.c | 16 +++++++++++-----
4 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/drivers/lguest/core.c b/drivers/lguest/core.c
index cb4c670..07a4c22 100644
--- a/drivers/lguest/core.c
+++ b/drivers/lguest/core.c
@@ -174,8 +174,10 @@ void __lgwrite(struct lguest *lg, unsigned long addr, const void *b,
/*H:030 Let's jump straight to the the main loop which runs the Guest.
* Remember, this is called by the Launcher reading /dev/lguest, and we keep
* going around and around until something interesting happens. */
-int run_guest(struct lguest *lg, unsigned long __user *user)
+int run_guest(struct lg_vcpu *vcpu, unsigned long __user *user)
{
+ struct lguest *lg = vcpu->lg;
+
/* We stop running once the Guest is dead. */
while (!lg->dead) {
/* First we run any hypercalls the Guest wants done. */
@@ -226,7 +228,7 @@ int run_guest(struct lguest *lg, unsigned long __user *user)
local_irq_disable();

/* Actually run the Guest until something happens. */
- lguest_arch_run_guest(lg);
+ lguest_arch_run_guest(vcpu);

/* Now we're ready to be interrupted or moved to other CPUs */
local_irq_enable();
diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h
index 8fc1c29..271d214 100644
--- a/drivers/lguest/lg.h
+++ b/drivers/lguest/lg.h
@@ -126,7 +126,7 @@ void __lgwrite(struct lguest *, unsigned long, const void *, unsigned);
} while(0)
/* (end of memory access helper routines) :*/

-int run_guest(struct lguest *lg, unsigned long __user *user);
+int run_guest(struct lg_vcpu *vcpu, unsigned long __user *user);

/* Helper macros to obtain the first 12 or the last 20 bits, this is only the
* first step in the migration to the kernel types. pte_pfn is already defined
@@ -177,7 +177,7 @@ void page_table_guest_data_init(struct lguest *lg);
/* <arch>/core.c: */
void lguest_arch_host_init(void);
void lguest_arch_host_fini(void);
-void lguest_arch_run_guest(struct lguest *lg);
+void lguest_arch_run_guest(struct lg_vcpu *vcpu);
void lguest_arch_handle_trap(struct lguest *lg);
int lguest_arch_init_hypercalls(struct lguest *lg);
int lguest_arch_do_hcall(struct lguest *lg, struct hcall_args *args);
diff --git a/drivers/lguest/lguest_user.c b/drivers/lguest/lguest_user.c
index 34be8e7..216514b 100644
--- a/drivers/lguest/lguest_user.c
+++ b/drivers/lguest/lguest_user.c
@@ -55,11 +55,19 @@ static int user_send_irq(struct lguest *lg, const unsigned long __user *input)
static ssize_t read(struct file *file, char __user *user, size_t size,loff_t*o)
{
struct lguest *lg = file->private_data;
+ struct lg_vcpu *vcpu = NULL;
+ unsigned int vcpu_id = *o;

/* You must write LHREQ_INITIALIZE first! */
if (!lg)
return -EINVAL;

+ /* Watch out for arbitrary vcpu indexes! */
+ if (vcpu_id > lg->nr_vcpus)
+ return -EINVAL;
+
+ vcpu = &lg->vcpus[vcpu_id];
+
/* If you're not the task which owns the Guest, go away. */
if (current != lg->tsk)
return -EPERM;
@@ -85,7 +93,7 @@ static ssize_t read(struct file *file, char __user *user, size_t size,loff_t*o)
lg->pending_notify = 0;

/* Run the Guest until something interesting happens. */
- return run_guest(lg, (unsigned long __user *)user);
+ return run_guest(vcpu, (unsigned long __user *)user);
}

static int vcpu_start(struct lg_vcpu *vcpu, int vcpu_id,
diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c
index 482aec2..3496cd9 100644
--- a/drivers/lguest/x86/core.c
+++ b/drivers/lguest/x86/core.c
@@ -73,8 +73,10 @@ static DEFINE_PER_CPU(struct lguest *, last_guest);
* since it last ran. We saw this set in interrupts_and_traps.c and
* segments.c.
*/
-static void copy_in_guest_info(struct lguest *lg, struct lguest_pages *pages)
+static void copy_in_guest_info(struct lg_vcpu *vcpu,
+ struct lguest_pages *pages)
{
+ struct lguest *lg = vcpu->lg;
/* Copying all this data can be quite expensive. We usually run the
* same Guest we ran last time (and that Guest hasn't run anywhere else
* meanwhile). If that's not the case, we pretend everything in the
@@ -113,14 +115,16 @@ static void copy_in_guest_info(struct lguest *lg, struct lguest_pages *pages)
}

/* Finally: the code to actually call into the Switcher to run the Guest. */
-static void run_guest_once(struct lguest *lg, struct lguest_pages *pages)
+static void run_guest_once(struct lg_vcpu *vcpu,
+ struct lguest_pages *pages)
{
/* This is a dummy value we need for GCC's sake. */
unsigned int clobber;
+ struct lguest *lg = vcpu->lg;

/* Copy the guest-specific information into this CPU's "struct
* lguest_pages". */
- copy_in_guest_info(lg, pages);
+ copy_in_guest_info(vcpu, pages);

/* Set the trap number to 256 (impossible value). If we fault while
* switching to the Guest (bad segment registers or bug), this will
@@ -161,8 +165,10 @@ static void run_guest_once(struct lguest *lg, struct lguest_pages *pages)

/*H:040 This is the i386-specific code to setup and run the Guest. Interrupts
* are disabled: we own the CPU. */
-void lguest_arch_run_guest(struct lguest *lg)
+void lguest_arch_run_guest(struct lg_vcpu *vcpu)
{
+ struct lguest *lg = vcpu->lg;
+
/* Remember the awfully-named TS bit? If the Guest has asked to set it
* we set it now, so we can trap and pass that trap to the Guest if it
* uses the FPU. */
@@ -180,7 +186,7 @@ void lguest_arch_run_guest(struct lguest *lg)
/* Now we actually run the Guest. It will return when something
* interesting happens, and we can examine its registers to see what it
* was doing. */
- run_guest_once(lg, lguest_pages(raw_smp_processor_id()));
+ run_guest_once(vcpu, lguest_pages(raw_smp_processor_id()));

/* Note that the "regs" pointer contains two extra entries which are
* not really registers: a trap number which says what interrupt or
--
1.5.0.6