On Mon, Oct 20, 2008 at 07:04:43PM +0200, Alexander Graf wrote:
> These are helpers for the nested SVM implementation.
>
> - nsvm_printk implements a debug printk variant
> - nested_svm_do calls a handler that can accesses gpa-based memory
>
> v3 makes use of the new permission checker
>
> Signed-off-by: Alexander Graf <[EMAIL PROTECTED]>
> ---
> arch/x86/kvm/svm.c | 88
> ++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 files changed, 88 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 4ee5376..a00421b 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -48,6 +48,16 @@ MODULE_LICENSE("GPL");
>
> #define DEBUGCTL_RESERVED_BITS (~(0x3fULL))
>
> +/* Turn on to get debugging output*/
> +/* #define NESTED_DEBUG */
> +
> +#ifdef NESTED_DEBUG
> +#define nsvm_printk(fmt, args...) printk(KERN_INFO fmt, ## args)
> +#else
> +static inline void nsvm_printk(char *fmt, ...) {
> +}
> +#endif
> +
> /* enable NPT for AMD64 and X86 with PAE */
> #if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
> static bool npt_enabled = true;
> @@ -1145,6 +1155,84 @@ static int vmmcall_interception(struct vcpu_svm *svm,
> struct kvm_run *kvm_run)
> return 1;
> }
>
> +static int nested_svm_check_permissions(struct vcpu_svm *svm)
> +{
> + if (svm->vmcb->save.cpl) {
> + printk(KERN_ERR "%s: invalid cpl 0x%x at ip 0x%lx\n",
> + __func__, svm->vmcb->save.cpl, kvm_rip_read(&svm->vcpu));
This is not really a kernel error. Please remove this printk. It allows
the guest to flood the logfiles of the host.
> + kvm_queue_exception(&svm->vcpu, GP_VECTOR);
> + return 1;
> + }
> +
> + if (!(svm->vcpu.arch.shadow_efer & MSR_EFER_SVME_MASK)
> + || !is_paging(&svm->vcpu)) {
> + kvm_queue_exception(&svm->vcpu, UD_VECTOR);
> + return 1;
> + }
> +
> + return 0;
> +}
> +
> +static struct page *nested_svm_get_page(struct vcpu_svm *svm, u64 gpa)
> +{
> + struct page *page;
> +
> + down_read(¤t->mm->mmap_sem);
> + page = gfn_to_page(svm->vcpu.kvm, gpa >> PAGE_SHIFT);
> + up_read(¤t->mm->mmap_sem);
> +
> + if (is_error_page(page)) {
> + printk(KERN_ERR "%s: could not find page at 0x%llx\n",
> + __func__, gpa);
> + kvm_release_page_clean(page);
> + kvm_queue_exception(&svm->vcpu, GP_VECTOR);
> + return NULL;
> + }
> + return page;
> +}
> +
> +static int nested_svm_do(struct vcpu_svm *svm,
> + u64 arg1_gpa, u64 arg2_gpa, void *opaque,
> + int (*handler)(struct vcpu_svm *svm,
> + void *arg1,
> + void *arg2,
> + void *opaque))
> +{
> + struct page *arg1_page;
> + struct page *arg2_page = NULL;
> + void *arg1;
> + void *arg2 = NULL;
> + int retval;
> +
> + arg1_page = nested_svm_get_page(svm, arg1_gpa);
> + if(arg1_page == NULL)
> + return 1;
> +
> + if (arg2_gpa) {
> + arg2_page = nested_svm_get_page(svm, arg2_gpa);
> + if(arg2_page == NULL) {
> + kvm_release_page_clean(arg1_page);
> + return 1;
> + }
> + }
> +
> + arg1 = kmap_atomic(arg1_page, KM_USER0);
> + if (arg2_gpa)
> + arg2 = kmap_atomic(arg2_page, KM_USER1);
> +
> + retval = handler(svm, arg1, arg2, opaque);
> +
> + kunmap_atomic(arg1, KM_USER0);
> + if (arg2_gpa)
> + kunmap_atomic(arg2, KM_USER1);
> +
> + kvm_release_page_dirty(arg1_page);
> + if (arg2_gpa)
> + kvm_release_page_dirty(arg2_page);
> +
> + return retval;
> +}
> +
> static int invalid_op_interception(struct vcpu_svm *svm,
> struct kvm_run *kvm_run)
> {
> --
> 1.5.6
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