From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jes Sorensen Date: Tue, 16 Dec 2008 15:45:47 +0000 Subject: [patch] fix kvm_arch_vcpu_ioctl_[gs]et_regs() - v2 Message-Id: <4947CD2B.5030300@sgi.com> MIME-Version: 1 Content-Type: multipart/mixed; boundary="------------030008040808090706040904" List-Id: To: kvm-ia64@vger.kernel.org This is a multi-part message in MIME format. --------------030008040808090706040904 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Avi Kivity wrote: > This makes several tons of sense, but breaks backwards compatibility. > If I understand correctly, get/set was never used so this shouldn't matter? > > I suggest reserving some space at the end of kvm_regs in case further > state needs to be added. > > Please add a KVM_CAP_ entry to advertise the fixup. This way userspace > can determine that it's compiling or running on an old kernel and error > out gracefully. Hi Avi, Here's an update version of this patch, which leaves some space for future extensions in struct kvm_regs. The KVM_CAP is unnecessary as GET/SET_REGS never worked on ia64. Cheers, Jes --------------030008040808090706040904 Content-Type: text/plain; name="6000-kvm-ia64-get-regs-locking.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="6000-kvm-ia64-get-regs-locking.patch" 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. In addition reserve extra space for future extensions. The change of layout of struct kvm_regs doesn't require adding a new CAP since get/set regs never worked on ia64 until now. 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 --- arch/ia64/include/asm/kvm.h | 6 ++++-- arch/ia64/kvm/kvm-ia64.c | 40 ++++++++++------------------------------ 2 files changed, 14 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 +231,10 @@ unsigned long fp_psr; /*used for lazy float register */ unsigned long saved_gp; /*for phycial emulation */ + + unsigned long reserved[64]; /* for future use */ + + 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, ®s->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(®s->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) --------------030008040808090706040904--