Xen ≫ Xen

For a brief summary of Xapi terminology, see: https://xapi-project.github.io/xen-api/overview.html#object-model-overview Xapi contains functionality to backup and restore metadata about Virtual Machines and Storage Repositories (SRs). The meta...

A cross-privilege Spectre v2 vulnerability allows attackers to bypass all deployed mitigations, including the recent Fine(IBT), and to leak arbitrary Linux kernel memory on Intel systems.

PVH guests have their ACPI tables constructed by the toolstack. The construction involves building the tables in local memory, which are then copied into guest memory. While actually used parts of the local memory are filled in correctly, excess sp...

The hypervisor contains code to accelerate VGA memory accesses for HVM guests, when the (virtual) VGA is in "standard" mode. Locking involved there has an unusual discipline, leaving a lock acquired past the return from the function that acquired it...

In x86's APIC (Advanced Programmable Interrupt Controller) architecture, error conditions are reported in a status register. Furthermore, the OS can opt to receive an interrupt when a new error occurs. It is possible to configure the error interrup...

When multiple devices share resources and one of them is to be passed through to a guest, security of the entire system and of respective guests individually cannot really be guaranteed without knowing internals of any of the involved guests. Theref...

Certain PCI devices in a system might be assigned Reserved Memory Regions (specified via Reserved Memory Region Reporting, "RMRR") for Intel VT-d or Unity Mapping ranges for AMD-Vi. These are typically used for platform tasks such as legacy USB emul...

An optional feature of PCI MSI called "Multiple Message" allows a device to use multiple consecutive interrupt vectors. Unlike for MSI-X, the setting up of these consecutive vectors needs to happen all in one go. In this handling an error path coul...

Because of a logical error in XSA-407 (Branch Type Confusion), the mitigation is not applied properly when it is intended to be used. XSA-434 (Speculative Return Stack Overflow) uses the same infrastructure, so is equally impacted. For more details,...

Unlike 32-bit PV guests, HVM guests may switch freely between 64-bit and other modes. This in particular means that they may set registers used to pass 32-bit-mode hypercall arguments to values outside of the range 32-bit code would be able to set t...