similar to: [RFC, PATCH 12/24] i386 Vmi processor header

Fairly straightforward code motion in system.h into the sub-arch layer. Affected functionality include control register accessors, which are virtualizable but with great overhead due to the #GP cost; wbinvd, and most importantly, halt and interrupt control, which is non-virtualizable. Since read_cr4_safe can never fault on a VMI kernel (P5+ processor is required for VMI), we can omit the fault

Fairly straightforward code motion in system.h into the sub-arch layer. Affected functionality include control register accessors, which are virtualizable but with great overhead due to the #GP cost; wbinvd, and most importantly, halt and interrupt control, which is non-virtualizable. Since read_cr4_safe can never fault on a VMI kernel (P5+ processor is required for VMI), we can omit the fault

Descriptor and trap table cleanups. Add cleanly written accessors for IDT and GDT gates so the subarch may override them. Note that this allows the hypervisor to transparently tweak the DPL of the descriptors as well as the RPL of segments in those descriptors, with no unnecessary kernel code modification. It also allows the hypervisor implementation of the VMI to tweak the gates, allowing for

Descriptor and trap table cleanups. Add cleanly written accessors for IDT and GDT gates so the subarch may override them. Note that this allows the hypervisor to transparently tweak the DPL of the descriptors as well as the RPL of segments in those descriptors, with no unnecessary kernel code modification. It also allows the hypervisor implementation of the VMI to tweak the gates, allowing for

Move APIC read / write accessors to sub-arch layer. Note that we don't bother to implement apic_write_atomic any different, as it is only present to work around old processor erratums (Pentium Processor Spec update 11AP), and VMI kernels do not offer support for this class of processor. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Daniel Arai <arai@vmware.com>

Move APIC read / write accessors to sub-arch layer. Note that we don't bother to implement apic_write_atomic any different, as it is only present to work around old processor erratums (Pentium Processor Spec update 11AP), and VMI kernels do not offer support for this class of processor. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Daniel Arai <arai@vmware.com>

In a virtualized environment, virtual machines will time share the system with each other and with other processes running on the host system. Therefore, a VM's virtual CPUs (VCPUs) will be executing on the host's physical CPUs (pcpus) for only some portion of time. The VMI exposes a paravirtual view of time to the guest operating systems so that they may operate more effectively in a

In a virtualized environment, virtual machines will time share the system with each other and with other processes running on the host system. Therefore, a VM's virtual CPUs (VCPUs) will be executing on the host's physical CPUs (pcpus) for only some portion of time. The VMI exposes a paravirtual view of time to the guest operating systems so that they may operate more effectively in a

Fairly straightforward code motion of MSR / TSC / PMC accessors to the sub-arch level. Note that rdmsr/wrmsr_safe functions are not moved; Linux relies on the fault behavior here in the event that certain MSRs are not supported on hardware, and combining this with a VMI wrapper is overly complicated. The instructions are virtualizable with trap and emulate, not on critical code paths, and only

Fairly straightforward code motion of MSR / TSC / PMC accessors to the sub-arch level. Note that rdmsr/wrmsr_safe functions are not moved; Linux relies on the fault behavior here in the event that certain MSRs are not supported on hardware, and combining this with a VMI wrapper is overly complicated. The instructions are virtualizable with trap and emulate, not on critical code paths, and only

Move I/O instruction building to the sub-arch layer. Some very crafty but esoteric macros are used here to get optimized native instructions for port I/O in Linux be writing raw instruction strings. Adding a wrapper layer here is fairly easy, and makes the full range of I/O instructions available to the VMI interface. Also, slowing down I/O is not a useful operation in a VM, so there is a VMI

Move I/O instruction building to the sub-arch layer. Some very crafty but esoteric macros are used here to get optimized native instructions for port I/O in Linux be writing raw instruction strings. Adding a wrapper layer here is fairly easy, and makes the full range of I/O instructions available to the VMI interface. Also, slowing down I/O is not a useful operation in a VM, so there is a VMI

Again, more simple code movement. Move page invalidations and local and global flushes to the sub-arch layer. Note global here does not mean SMP, but the global bit of the page table entry. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.16-rc5/include/asm-i386/tlbflush.h =================================================================== ---

Again, more simple code movement. Move page invalidations and local and global flushes to the sub-arch layer. Note global here does not mean SMP, but the global bit of the page table entry. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.16-rc5/include/asm-i386/tlbflush.h =================================================================== ---

Macros to use VMI calls from assembly and C languages are introduced. The macros are quite complex, but the end result is rather impressive. The result is that when compiling a VMI kernel, the native code is emitted inline, with no function call overhead, and some wiggle room for register allocation. The hypervisor compatibility code is emitted out of line into a separate section, and patched

Macros to use VMI calls from assembly and C languages are introduced. The macros are quite complex, but the end result is rather impressive. The result is that when compiling a VMI kernel, the native code is emitted inline, with no function call overhead, and some wiggle room for register allocation. The hypervisor compatibility code is emitted out of line into a separate section, and patched

MMU code movement. Unfortunately, this one is a little bit more complicated than the rest. We have to override the default accessors that directly write to page table entries. Because of the 2/3-level PAE split in Linux, this turned out to be really ugly at first, but by allowing the sub-arch layer to override the definitions and keeping the native definitions in place, the code becomes much

MMU code movement. Unfortunately, this one is a little bit more complicated than the rest. We have to override the default accessors that directly write to page table entries. Because of the 2/3-level PAE split in Linux, this turned out to be really ugly at first, but by allowing the sub-arch layer to override the definitions and keeping the native definitions in place, the code becomes much

Use para_fill instead of directly setting the APIC ops to the result of the vmi_get_function call - this allows one to implement a VMI ROM without implementing APIC functions, just using the native APIC functions. While doing this, I realized that there is a lot more cleanup that should have been done. Basically, we should never assume that the ROM implements a specific set of functions, and

Use para_fill instead of directly setting the APIC ops to the result of the vmi_get_function call - this allows one to implement a VMI ROM without implementing APIC functions, just using the native APIC functions. While doing this, I realized that there is a lot more cleanup that should have been done. Basically, we should never assume that the ROM implements a specific set of functions, and