[patch] fix kvm_arch_vcpu_ioctl_[gs]et_regs()

[Jes Sorensen <jes@xxxxxxx>]

Hi,

This patch makes these two macros do something sensible on ia64 and
work the way qemu expects to use them. The old versions clearly couldn't
have worked since the get_regs() call expected pointers in the kvm_regs
struct which were never copied in.

Cheers,
Jes

Fix kvm_arch_vcpu_ioctl_[gs]et_regs() to do something meaningful on
ia64. Old versions could never have worked since they required
pointers to be set in the ioctl payload which were never being set by
the ioctl handler for get_regs.

This version doesn't support copying the KVM kernel stack in/out of
the kernel. This should be implemented in a seperate ioctl call if
ever needed.

Signed-off-by: Jes Sorensen <jes@xxxxxxx>

---
 arch/ia64/include/asm/kvm.h |    4 ++--
 arch/ia64/kvm/kvm-ia64.c    |   40 ++++++++++------------------------------
 2 files changed, 12 insertions(+), 32 deletions(-)

Index: linux-2.6.git/arch/ia64/include/asm/kvm.h
===================================================================
--- linux-2.6.git.orig/arch/ia64/include/asm/kvm.h
+++ linux-2.6.git/arch/ia64/include/asm/kvm.h
@@ -199,8 +199,6 @@
 };
 
 struct kvm_regs {
-	char *saved_guest;
-	char *saved_stack;
 	struct saved_vpd vpd;
 	/*Arch-regs*/
 	int mp_state;
@@ -233,6 +231,8 @@
 	unsigned long fp_psr;       /*used for lazy float register */
 	unsigned long saved_gp;
 	/*for phycial  emulation */
+
+	union context saved_guest;
 };
 
 struct kvm_sregs {
Index: linux-2.6.git/arch/ia64/kvm/kvm-ia64.c
===================================================================
--- linux-2.6.git.orig/arch/ia64/kvm/kvm-ia64.c
+++ linux-2.6.git/arch/ia64/kvm/kvm-ia64.c
@@ -867,9 +867,8 @@
 
 int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 {
-	int i;
 	struct vpd *vpd = to_host(vcpu->kvm, vcpu->arch.vpd);
-	int r;
+	int i;
 
 	vcpu_load(vcpu);
 
@@ -886,18 +885,7 @@
 
 	vpd->vpr = regs->vpd.vpr;
 
-	r = -EFAULT;
-	r = copy_from_user(&vcpu->arch.guest, regs->saved_guest,
-						sizeof(union context));
-	if (r)
-		goto out;
-	r = copy_from_user(vcpu + 1, regs->saved_stack +
-			sizeof(struct kvm_vcpu),
-			KVM_STK_OFFSET - sizeof(struct kvm_vcpu));
-	if (r)
-		goto out;
-	vcpu->arch.exit_data =
-		((struct kvm_vcpu *)(regs->saved_stack))->arch.exit_data;
+	memcpy(&vcpu->arch.guest, &regs->saved_guest, sizeof(union context));
 
 	RESTORE_REGS(mp_state);
 	RESTORE_REGS(vmm_rr);
@@ -931,9 +919,8 @@
 	set_bit(KVM_REQ_RESUME, &vcpu->requests);
 
 	vcpu_put(vcpu);
-	r = 0;
-out:
-	return r;
+
+	return 0;
 }
 
 long kvm_arch_vm_ioctl(struct file *filp,
@@ -1418,9 +1405,9 @@
 
 int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 {
-	int i;
-	int r;
 	struct vpd *vpd = to_host(vcpu->kvm, vcpu->arch.vpd);
+	int i;
+
 	vcpu_load(vcpu);
 
 	for (i = 0; i < 16; i++) {
@@ -1435,14 +1422,8 @@
 	regs->vpd.vpsr = vpd->vpsr;
 	regs->vpd.vpr = vpd->vpr;
 
-	r = -EFAULT;
-	r = copy_to_user(regs->saved_guest, &vcpu->arch.guest,
-					sizeof(union context));
-	if (r)
-		goto out;
-	r = copy_to_user(regs->saved_stack, (void *)vcpu, KVM_STK_OFFSET);
-	if (r)
-		goto out;
+	memcpy(&regs->saved_guest, &vcpu->arch.guest, sizeof(union context));
+
 	SAVE_REGS(mp_state);
 	SAVE_REGS(vmm_rr);
 	memcpy(regs->itrs, vcpu->arch.itrs, sizeof(struct thash_data) * NITRS);
@@ -1470,10 +1451,9 @@
 	SAVE_REGS(metaphysical_saved_rr4);
 	SAVE_REGS(fp_psr);
 	SAVE_REGS(saved_gp);
+
 	vcpu_put(vcpu);
-	r = 0;
-out:
-	return r;
+	return 0;
 }
 
 void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)