On 20/11/14 10:13, Jan Beulich wrote:
> This extends commit 5283b310 ("x86/HVM: only kill guest when unknown VM
> exit occurred in guest kernel mode") to further cases, including the
> failed VM entry one that XSA-110 was needed to be issued for.
>
> Signed-off-by: Jan Beulich <jbeul...@suse.com>
>
> --- a/xen/arch/x86/hvm/svm/svm.c
> +++ b/xen/arch/x86/hvm/svm/svm.c
> @@ -90,6 +90,15 @@ static bool_t amd_erratum383_found __rea
> static uint64_t osvw_length, osvw_status;
> static DEFINE_SPINLOCK(osvw_lock);
>
> +/* Only crash the guest if the problem originates in kernel mode. */
> +static void svm_crash_or_gp(struct vcpu *v)
> +{
> + if ( vmcb_get_cpl(v->arch.hvm_svm.vmcb) )
> + hvm_inject_hw_exception(TRAP_invalid_op, HVM_DELIVER_NO_ERROR_CODE);
This (and its VMX counterpart) should either deliver a #GP fault, or
have its name changed to not imply a #GP fault.
How about "crash_or_fault()" as an alternative which is slightly less
specific?
~Andrew
> + else
> + domain_crash(v->domain);
> +}
> +
> void __update_guest_eip(struct cpu_user_regs *regs, unsigned int inst_len)
> {
> struct vcpu *curr = current;
> @@ -100,7 +109,7 @@ void __update_guest_eip(struct cpu_user_
> if ( unlikely(inst_len > 15) )
> {
> gdprintk(XENLOG_ERR, "Bad instruction length %u\n", inst_len);
> - domain_crash(curr->domain);
> + svm_crash_or_gp(curr);
> return;
> }
>
> @@ -1505,7 +1514,7 @@ static void svm_do_nested_pgfault(struct
> gdprintk(XENLOG_ERR,
> "SVM violation gpa %#"PRIpaddr", mfn %#lx, type %i\n",
> gpa, mfn_x(mfn), p2mt);
> - domain_crash(v->domain);
> + svm_crash_or_gp(v);
> }
>
> static void svm_fpu_dirty_intercept(void)
> @@ -2647,7 +2656,7 @@ void svm_vmexit_handler(struct cpu_user_
> printk(XENLOG_G_ERR
> "%pv: Error %d handling NPF (gpa=%08lx ec=%04lx)\n",
> v, rc, vmcb->exitinfo2, vmcb->exitinfo1);
> - domain_crash(v->domain);
> + svm_crash_or_gp(v);
> }
> v->arch.hvm_svm.cached_insn_len = 0;
> break;
> @@ -2680,11 +2689,7 @@ void svm_vmexit_handler(struct cpu_user_
> "exitinfo1 = %#"PRIx64", exitinfo2 = %#"PRIx64"\n",
> exit_reason,
> (u64)vmcb->exitinfo1, (u64)vmcb->exitinfo2);
> - if ( vmcb_get_cpl(vmcb) )
> - hvm_inject_hw_exception(TRAP_invalid_op,
> - HVM_DELIVER_NO_ERROR_CODE);
> - else
> - domain_crash(v->domain);
> + svm_crash_or_gp(v);
> break;
> }
>
> --- a/xen/arch/x86/hvm/vmx/vmx.c
> +++ b/xen/arch/x86/hvm/vmx/vmx.c
> @@ -134,6 +134,18 @@ static void vmx_vcpu_destroy(struct vcpu
> passive_domain_destroy(v);
> }
>
> +/* Only crash the guest if the problem originates in kernel mode. */
> +static void vmx_crash_or_gp(struct vcpu *v)
> +{
> + struct segment_register ss;
> +
> + vmx_get_segment_register(v, x86_seg_ss, &ss);
> + if ( ss.attr.fields.dpl )
> + hvm_inject_hw_exception(TRAP_invalid_op, HVM_DELIVER_NO_ERROR_CODE);
> + else
> + domain_crash(v->domain);
> +}
> +
> static DEFINE_PER_CPU(struct vmx_msr_state, host_msr_state);
>
> static const u32 msr_index[] =
> @@ -2474,7 +2486,7 @@ static void ept_handle_violation(unsigne
> if ( qualification & EPT_GLA_VALID )
> gdprintk(XENLOG_ERR, " --- GLA %#lx\n", gla);
>
> - domain_crash(d);
> + vmx_crash_or_gp(current);
> }
>
> static void vmx_failed_vmentry(unsigned int exit_reason,
> @@ -2508,7 +2520,7 @@ static void vmx_failed_vmentry(unsigned
> vmcs_dump_vcpu(curr);
> printk("**************************************\n");
>
> - domain_crash(curr->domain);
> + vmx_crash_or_gp(curr);
> }
>
> void vmx_enter_realmode(struct cpu_user_regs *regs)
> @@ -3161,19 +3173,8 @@ void vmx_vmexit_handler(struct cpu_user_
> /* fall through */
> default:
> exit_and_crash:
> - {
> - struct segment_register ss;
> -
> - gdprintk(XENLOG_WARNING, "Bad vmexit (reason %#lx)\n",
> - exit_reason);
> -
> - vmx_get_segment_register(v, x86_seg_ss, &ss);
> - if ( ss.attr.fields.dpl )
> - hvm_inject_hw_exception(TRAP_invalid_op,
> - HVM_DELIVER_NO_ERROR_CODE);
> - else
> - domain_crash(v->domain);
> - }
> + gdprintk(XENLOG_WARNING, "Bad vmexit (reason %#lx)\n", exit_reason);
> + vmx_crash_or_gp(v);
> break;
> }
>
>
>
>
>
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