Re: [Xen-devel] [PATCH for 4.9 4/6] x86/svm: Introduce svm_emul_swint_injection()

[Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>]

> +static void svm_emul_swint_injection(struct x86_event *event)
> +{
> +    struct vcpu *curr = current;
> +    struct vmcb_struct *vmcb = curr->arch.hvm_svm.vmcb;
> +    struct cpu_user_regs *regs = guest_cpu_user_regs();
> +
> +    unsigned int trap = event->vector, type = event->type;
> +    unsigned int fault = TRAP_gp_fault, ec = 0;
> +
> +    if ( vmcb->_cr0 & X86_CR0_PE ) /* TODO: support real-mode injection? */


if ( !(vmcb->_cr0 & X86_CR0_PE) )
    goto raise_exception;


will avoid extra indentation level;

> +    {
> +        pagefault_info_t pf;
> +        struct segment_register idtr;
> +        unsigned int idte_size, idte_offset;
> +        unsigned long idte_linear_addr;
> +        struct { uint32_t a, b, c, d; } idte = {};
> +        bool lm = vmcb->_efer & EFER_LMA;
> +        enum hvm_segmentation_mode seg_mode =
> +            lm ? hvm_seg_mode_long : hvm_seg_mode_prot;
> +        int rc;
> +
> +        idte_size = lm ? 16 : 8;
> +        idte_offset = trap * idte_size;
> +
> +        /* ICEBP sets the External Event bit despite being an instruction. */
> +        ec = (trap << 3) | X86_XEC_IDT |
> +            (type == X86_EVENTTYPE_PRI_SW_EXCEPTION ? X86_XEC_EXT : 0);
> +
> +        /*
> +         * TODO: This does not cover the v8086 mode with CR4.VME case
> +         * correctly, but falls on the safe side from the point of view of a
> +         * 32bit OS.  Someone with many TUITs can see about reading the TSS
> +         * Software Interrupt Redirection bitmap.
> +         */
> +        if ( (regs->eflags & X86_EFLAGS_VM) &&
> +             MASK_EXTR(regs->eflags, X86_EFLAGS_IOPL) != 3 )
> +            goto raise_exception;
> +
> +        /*
> +         * Read all 8/16 bytes so the idtr limit check is applied properly to
> +         * this entry, even though don't look all the words read.

I think some words are missing here.

-boris


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