- 08 Dec, 2016 2 commits
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Kyle Huey authored
The functions being moved ahead of skip_emulated_instruction here don't need updated IPs, and skipping the emulated instruction at the end will make it easier to return its value. Signed-off-by:
Kyle Huey <khuey@kylehuey.com> Signed-off-by:
Radim Krčmář <rkrcmar@redhat.com>
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Kyle Huey authored
Once skipping the emulated instruction can potentially trigger an exit to userspace (via KVM_GUESTDBG_SINGLESTEP) kvm_emulate_cpuid will need to propagate a return value. Signed-off-by:
Kyle Huey <khuey@kylehuey.com> Signed-off-by:
Radim Krčmář <rkrcmar@redhat.com>
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- 06 Dec, 2016 1 commit
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git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpcRadim Krčmář authored
Eliminate merge conflict between 9e5f6884 and ebe4535f.
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- 01 Dec, 2016 1 commit
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Paul Mackerras authored
This moves the prototypes for functions that are only called from assembler code out of asm/asm-prototypes.h into asm/kvm_ppc.h. The prototypes were added in commit ebe4535f ("KVM: PPC: Book3S HV: sparse: prototypes for functions called from assembler", 2016-10-10), but given that the functions are KVM functions, having them in a KVM header will be better for long-term maintenance. Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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- 29 Nov, 2016 2 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpcRadim Krčmář authored
PPC KVM update for 4.10: * Support for KVM guests on POWER9 using the hashed page table MMU. * Updates and improvements to the halt-polling support on PPC, from Suraj Jitindar Singh. * An optimization to speed up emulated MMIO, from Yongji Xie. * Various other minor cleanups.
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git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linuxRadim Krčmář authored
KVM: s390: Changes for 4.10 (via kvm/next) Two small optimizations to not do register reloading in vcpu_put/get, instead do it in the ioctl path. This reduces the overhead for schedule-intense workload that does not exit to QEMU. (e.g. KVM guest with eventfd/irqfd that does a lot of context switching with vhost or iothreads).
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- 28 Nov, 2016 6 commits
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Suraj Jitindar Singh authored
There is currently no documentation about the halt polling capabilities of the kvm module. Add some documentation describing the mechanism as well as the module parameters to all better understanding of how halt polling should be used and the effect of tuning the module parameters. Signed-off-by:
Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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Suraj Jitindar Singh authored
Fix comment block to match kernel comment style. Fix print format from signed to unsigned. Signed-off-by:
Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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Suraj Jitindar Singh authored
KVM_HALT_POLL_NS_DEFAULT is an arch specific constant which sets the default value of the halt_poll_ns kvm module parameter which determines the global maximum halt polling interval. The current value for powerpc is 500000 (500us) which means that any repetitive workload with a period of less than that can drive the cpu usage to 100% where it may have been mostly idle without halt polling. This presents the possibility of a large increase in power usage with a comparatively small performance benefit. Reduce the default to 10000 (10us) and a user can tune this themselves to set their affinity for halt polling based on the trade off between power and performance which they are willing to make. Signed-off-by:
Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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Suraj Jitindar Singh authored
The kvm module parameter halt_poll_ns defines the global maximum halt polling interval and can be dynamically changed by writing to the /sys/module/kvm/parameters/halt_poll_ns sysfs file. However in kvm-hv this module parameter value is only ever checked when we grow the current polling interval for the given vcore. This means that if we decrease the halt_poll_ns value below the current polling interval we won't see any effect unless we try to grow the polling interval above the new max at some point or it happens to be shrunk below the halt_poll_ns value. Update the halt polling code so that we always check for a new module param value of halt_poll_ns and set the current halt polling interval to it if it's currently greater than the new max. This means that it's redundant to also perform this check in the grow_halt_poll_ns() function now. Signed-off-by:
Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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Suraj Jitindar Singh authored
The previous patch exported the variables which back the module parameters of the generic kvm module. Now use these variables in the kvm-hv module so that any change to the generic module parameters will also have the same effect for the kvm-hv module. This removes the duplication of the kvm module parameters which was redundant and should reduce confusion when tuning them. Signed-off-by:
Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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Suraj Jitindar Singh authored
The kvm module has the parameters halt_poll_ns, halt_poll_ns_grow, and halt_poll_ns_shrink. Halt polling was recently added to the powerpc kvm-hv module and these parameters were essentially duplicated for that. There is no benefit to this duplication and it can lead to confusion when trying to tune halt polling. Thus move the definition of these variables to kvm_host.h and export them. This will allow the kvm-hv module to use the same module parameters by accessing these variables, which will be implemented in the next patch, meaning that they will no longer be duplicated. Signed-off-by:
Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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- 24 Nov, 2016 5 commits
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Tom Lendacky authored
Update the I/O interception support to add the kvm_fast_pio_in function to speed up the in instruction similar to the out instruction. Signed-off-by:
Tom Lendacky <thomas.lendacky@amd.com> Reviewed-by:
Borislav Petkov <bp@suse.de> Signed-off-by:
Brijesh Singh <brijesh.singh@amd.com> Signed-off-by:
Radim Krčmář <rkrcmar@redhat.com>
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Tom Lendacky authored
AMD hardware adds two additional bits to aid in nested page fault handling. Bit 32 - NPF occurred while translating the guest's final physical address Bit 33 - NPF occurred while translating the guest page tables The guest page tables fault indicator can be used as an aid for nested virtualization. Using V0 for the host, V1 for the first level guest and V2 for the second level guest, when both V1 and V2 are using nested paging there are currently a number of unnecessary instruction emulations. When V2 is launched shadow paging is used in V1 for the nested tables of V2. As a result, KVM marks these pages as RO in the host nested page tables. When V2 exits and we resume V1, these pages are still marked RO. Every nested walk for a guest page table is treated as a user-level write access and this causes a lot of NPFs because the V1 page tables are marked RO in the V0 nested tables. While executing V1, when these NPFs occur KVM sees a write to a read-only page, emulates the V1 instruction and unprotects the page (marking it RW). This patch looks for cases where we get a NPF due to a guest page table walk where the page was marked RO. It immediately unprotects the page and resumes the guest, leading to far fewer instruction emulations when nested virtualization is used. Signed-off-by:
Tom Lendacky <thomas.lendacky@amd.com> Reviewed-by:
Borislav Petkov <bp@suse.de> Signed-off-by:
Brijesh Singh <brijesh.singh@amd.com> Signed-off-by:
Radim Krčmář <rkrcmar@redhat.com>
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David Gibson authored
At present KVM on powerpc always reports KVM_CAP_PPC_ALLOC_HTAB as enabled. However, the ioctl() it advertises (KVM_PPC_ALLOCATE_HTAB) only actually works on KVM HV. On KVM PR it will fail with ENOTTY. QEMU already has a workaround for this, so it's not breaking things in practice, but it would be better to advertise this correctly. Signed-off-by:
David Gibson <david@gibson.dropbear.id.au> Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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David Gibson authored
The KVM_PPC_PVINFO_FLAGS_EV_IDLE macro defines a bit for use in the flags field of struct kvm_ppc_pvinfo. However, changes since that was introduced have moved it away from that structure definition, which is confusing. Move it back next to the structure it belongs with. Signed-off-by:
David Gibson <david@gibson.dropbear.id.au> Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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Paul Mackerras authored
This adds the "again" parameter to the dummy version of kvmppc_check_passthru(), so that it matches the real version. This fixes compilation with CONFIG_BOOK3S_64_HV set but CONFIG_KVM_XICS=n. This includes asm/smp.h in book3s_hv_builtin.c to fix compilation with CONFIG_SMP=n. The explicit inclusion is necessary to provide definitions of hard_smp_processor_id() and get_hard_smp_processor_id() in UP configs. Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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- 23 Nov, 2016 13 commits
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Suraj Jitindar Singh authored
The function kvmppc_set_arch_compat() is used to determine the value of the processor compatibility register (PCR) for a guest running in a given compatibility mode. There is currently no support for v3.00 of the ISA. Add support for v3.00 of the ISA which adds an ISA v2.07 compatilibity mode to the PCR. We also add a check to ensure the processor we are running on is capable of emulating the chosen processor (for example a POWER7 cannot emulate a POWER8, similarly with a POWER8 and a POWER9). Based on work by: Paul Mackerras <paulus@ozlabs.org> [paulus@ozlabs.org - moved dummy PCR_ARCH_300 definition here; set guest_pcr_bit when arch_compat == 0, added comment.] Signed-off-by:
Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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Paul Mackerras authored
With POWER9, each CPU thread has its own MMU context and can be in the host or a guest independently of the other threads; there is still however a restriction that all threads must use the same type of address translation, either radix tree or hashed page table (HPT). Since we only support HPT guests on a HPT host at this point, we can treat the threads as being independent, and avoid all of the work of coordinating the CPU threads. To make this simpler, we introduce a new threads_per_vcore() function that returns 1 on POWER9 and threads_per_subcore on POWER7/8, and use that instead of threads_per_subcore or threads_per_core in various places. This also changes the value of the KVM_CAP_PPC_SMT capability on POWER9 systems from 4 to 1, so that userspace will not try to create VMs with multiple vcpus per vcore. (If userspace did create a VM that thought it was in an SMT mode, the VM might try to use the msgsndp instruction, which will not work as expected. In future it may be possible to trap and emulate msgsndp in order to allow VMs to think they are in an SMT mode, if only for the purpose of allowing migration from POWER8 systems.) With all this, we can now run guests on POWER9 as long as the host is running with HPT translation. Since userspace currently has no way to request radix tree translation for the guest, the guest has no choice but to use HPT translation. Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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Paul Mackerras authored
The new XIVE interrupt controller on POWER9 can direct external interrupts to the hypervisor or the guest. The interrupts directed to the hypervisor are controlled by an LPCR bit called LPCR_HVICE, and come in as a "hypervisor virtualization interrupt". This sets the LPCR bit so that hypervisor virtualization interrupts can occur while we are in the guest. We then also need to cope with exiting the guest because of a hypervisor virtualization interrupt. Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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Paul Mackerras authored
POWER9 replaces the various power-saving mode instructions on POWER8 (doze, nap, sleep and rvwinkle) with a single "stop" instruction, plus a register, PSSCR, which controls the depth of the power-saving mode. This replaces the use of the nap instruction when threads are idle during guest execution with the stop instruction, and adds code to set PSSCR to a value which will allow an SMT mode switch while the thread is idle (given that the core as a whole won't be idle in these cases). Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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Paul Mackerras authored
POWER9 includes a new interrupt controller, called XIVE, which is quite different from the XICS interrupt controller on POWER7 and POWER8 machines. KVM-HV accesses the XICS directly in several places in order to send and clear IPIs and handle interrupts from PCI devices being passed through to the guest. In order to make the transition to XIVE easier, OPAL firmware will include an emulation of XICS on top of XIVE. Access to the emulated XICS is via OPAL calls. The one complication is that the EOI (end-of-interrupt) function can now return a value indicating that another interrupt is pending; in this case, the XIVE will not signal an interrupt in hardware to the CPU, and software is supposed to acknowledge the new interrupt without waiting for another interrupt to be delivered in hardware. This adapts KVM-HV to use the OPAL calls on machines where there is no XICS hardware. When there is no XICS, we look for a device-tree node with "ibm,opal-intc" in its compatible property, which is how OPAL indicates that it provides XICS emulation. In order to handle the EOI return value, kvmppc_read_intr() has become kvmppc_read_one_intr(), with a boolean variable passed by reference which can be set by the EOI functions to indicate that another interrupt is pending. The new kvmppc_read_intr() keeps calling kvmppc_read_one_intr() until there are no more interrupts to process. The return value from kvmppc_read_intr() is the largest non-zero value of the returns from kvmppc_read_one_intr(). Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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Paul Mackerras authored
On POWER9, the msgsnd instruction is able to send interrupts to other cores, as well as other threads on the local core. Since msgsnd is generally simpler and faster than sending an IPI via the XICS, we use msgsnd for all IPIs sent by KVM on POWER9. Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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Paul Mackerras authored
POWER9 adds new capabilities to the tlbie (TLB invalidate entry) and tlbiel (local tlbie) instructions. Both instructions get a set of new parameters (RIC, PRS and R) which appear as bits in the instruction word. The tlbiel instruction now has a second register operand, which contains a PID and/or LPID value if needed, and should otherwise contain 0. This adapts KVM-HV's usage of tlbie and tlbiel to work on POWER9 as well as older processors. Since we only handle HPT guests so far, we need RIC=0 PRS=0 R=0, which ends up with the same instruction word as on previous processors, so we don't need to conditionally execute different instructions depending on the processor. The local flush on first entry to a guest in book3s_hv_rmhandlers.S is a loop which depends on the number of TLB sets. Rather than using feature sections to set the number of iterations based on which CPU we're on, we now work out this number at VM creation time and store it in the kvm_arch struct. That will make it possible to get the number from the device tree in future, which will help with compatibility with future processors. Since mmu_partition_table_set_entry() does a global flush of the whole LPID, we don't need to do the TLB flush on first entry to the guest on each processor. Therefore we don't set all bits in the tlb_need_flush bitmap on VM startup on POWER9. Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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Paul Mackerras authored
This adds code to handle two new guest-accessible special-purpose registers on POWER9: TIDR (thread ID register) and PSSCR (processor stop status and control register). They are context-switched between host and guest, and the guest values can be read and set via the one_reg interface. The PSSCR contains some fields which are guest-accessible and some which are only accessible in hypervisor mode. We only allow the guest-accessible fields to be read or set by userspace. Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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Paul Mackerras authored
Some special-purpose registers that were present and accessible by guests on POWER8 no longer exist on POWER9, so this adds feature sections to ensure that we don't try to context-switch them when going into or out of a guest on POWER9. These are all relatively obscure, rarely-used registers, but we had to context-switch them on POWER8 to avoid creating a covert channel. They are: SPMC1, SPMC2, MMCRS, CSIGR, TACR, TCSCR, and ACOP. Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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Paul Mackerras authored
On POWER9, the SDR1 register (hashed page table base address) is no longer used, and instead the hardware reads the HPT base address and size from the partition table. The partition table entry also contains the bits that specify the page size for the VRMA mapping, which were previously in the LPCR. The VPM0 bit of the LPCR is now reserved; the processor now always uses the VRMA (virtual real-mode area) mechanism for guest real-mode accesses in HPT mode, and the RMO (real-mode offset) mechanism has been dropped. When entering or exiting the guest, we now only have to set the LPIDR (logical partition ID register), not the SDR1 register. There is also no requirement now to transition via a reserved LPID value. Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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Paul Mackerras authored
This adapts the KVM-HV hashed page table (HPT) code to read and write HPT entries in the new format defined in Power ISA v3.00 on POWER9 machines. The new format moves the B (segment size) field from the first doubleword to the second, and trims some bits from the AVA (abbreviated virtual address) and ARPN (abbreviated real page number) fields. As far as possible, the conversion is done when reading or writing the HPT entries, and the rest of the code continues to use the old format. Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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Paul Mackerras authored
This merges in the ppc-kvm topic branch to get changes to arch/powerpc code that are necessary for adding POWER9 KVM support. Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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Michael Neuling authored
Define and set the POWER9 HFSCR doorbell bit so that guests can use msgsndp. ISA 3.0 calls this MSGP, so name it accordingly in the code. Signed-off-by:
Michael Neuling <mikey@neuling.org> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au>
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- 22 Nov, 2016 10 commits
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Michael Ellerman authored
ISA 3.0 defines a new PECE (Power-saving mode Exit Cause Enable) field in the LPCR (Logical Partitioning Control Register), called LPCR_PECE_HVEE (Hypervisor Virtualization Exit Enable). KVM code will need to know about this bit, so add a definition for it. Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au>
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Suraj Jitindar Singh authored
ISA 3.00 adds the logical PVR value 0x0f000005, so add a definition for this. Define PCR_ARCH_207 to reflect ISA 2.07 compatibility mode in the processor compatibility register (PCR). [paulus@ozlabs.org - moved dummy PCR_ARCH_300 value into next patch] Signed-off-by:
Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by:
Paul Mackerras <paulus@ozlabs.org> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au>
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Paul Mackerras authored
This defines real-mode versions of opal_int_get_xirr(), opal_int_eoi() and opal_int_set_mfrr(), for use by KVM real-mode code. It also exports opal_int_set_mfrr() so that the modular part of KVM can use it to send IPIs. Signed-off-by:
Paul Mackerras <paulus@ozlabs.org> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au>
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Paul Mackerras authored
POWER9 requires the host to set up a partition table, which is a table in memory indexed by logical partition ID (LPID) which contains the pointers to page tables and process tables for the host and each guest. This factors out the initialization of the partition table into a single function. This code was previously duplicated between hash_utils_64.c and pgtable-radix.c. This provides a function for setting a partition table entry, which is used in early MMU initialization, and will be used by KVM whenever a guest is created. This function includes a tlbie instruction which will flush all TLB entries for the LPID and all caches of the partition table entry for the LPID, across the system. This also moves a call to memblock_set_current_limit(), which was in radix_init_partition_table(), but has nothing to do with the partition table. By analogy with the similar code for hash, the call gets moved to near the end of radix__early_init_mmu(). It now gets called when running as a guest, whereas previously it would only be called if the kernel is running as the host. Signed-off-by:
Paul Mackerras <paulus@ozlabs.org> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au>
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Christian Borntraeger authored
Right now we switch the host fprs/vrs in kvm_arch_vcpu_load and switch back in kvm_arch_vcpu_put. This process is already optimized since commit 9977e886 ("s390/kernel: lazy restore fpu registers") avoiding double save/restores on schedule. We still reload the pointers and test the guest fpc on each context switch, though. We can minimize the cost of vcpu_load/put by doing the test in the VCPU_RUN ioctl itself. As most VCPU threads almost never exit to userspace in the common fast path, this allows to avoid this overhead for the common case (eventfd driven I/O, all exits including sleep handled in the kernel) - making kvm_arch_vcpu_load/put basically disappear in perf top. Also adapt the fpu get/set ioctls. Signed-off-by:
Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by:
Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by:
Christian Borntraeger <borntraeger@de.ibm.com>
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Christian Borntraeger authored
Right now we save the host access registers in kvm_arch_vcpu_load and load them in kvm_arch_vcpu_put. Vice versa for the guest access registers. On schedule this means, that we load/save access registers multiple times. e.g. VCPU_RUN with just one reschedule and then return does [from user space via VCPU_RUN] - save the host registers in kvm_arch_vcpu_load (via ioctl) - load the guest registers in kvm_arch_vcpu_load (via ioctl) - do guest stuff - decide to schedule/sleep - save the guest registers in kvm_arch_vcpu_put (via sched) - load the host registers in kvm_arch_vcpu_put (via sched) - save the host registers in switch_to (via sched) - schedule - return - load the host registers in switch_to (via sched) - save the host registers in kvm_arch_vcpu_load (via sched) - load the guest registers in kvm_arch_vcpu_load (via sched) - do guest stuff - decide to go to userspace - save the guest registers in kvm_arch_vcpu_put (via ioctl) - load the host registers in kvm_arch_vcpu_put (via ioctl) [back to user space] As the kernel does not use access registers, we can avoid this reloading and simply piggy back on switch_to (let it save the guest values instead of host values in thread.acrs) by moving the host/guest switch into the VCPU_RUN ioctl function. We now do [from user space via VCPU_RUN] - save the host registers in kvm_arch_vcpu_ioctl_run - load the guest registers in kvm_arch_vcpu_ioctl_run - do guest stuff - decide to schedule/sleep - save the guest registers in switch_to - schedule - return - load the guest registers in switch_to (via sched) - do guest stuff - decide to go to userspace - save the guest registers in kvm_arch_vcpu_ioctl_run - load the host registers in kvm_arch_vcpu_ioctl_run This seems to save about 10% of the vcpu_put/load functions according to perf. As vcpu_load no longer switches the acrs, We can also loading the acrs in kvm_arch_vcpu_ioctl_set_sregs. Suggested-by:
Fan Zhang <zhangfan@linux.vnet.ibm.com> Reviewed-by:
Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by:
Christian Borntraeger <borntraeger@de.ibm.com>
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Bandan Das authored
Change unimplemented msrs messages to use pr_debug. If CONFIG_DYNAMIC_DEBUG is set, then these messages can be enabled at run time or else -DDEBUG can be used at compile time to enable them. These messages will still be printed if ignore_msrs=1. Signed-off-by:
Bandan Das <bsd@redhat.com> Reviewed-by:
Paolo Bonzini <pbonzini@redhat.com> Signed-off-by:
Radim Krčmář <rkrcmar@redhat.com>
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Jan Dakinevich authored
- Expose all invalidation types to the L1 - Reject invvpid instruction, if L1 passed zero vpid value to single context invalidations Signed-off-by:
Jan Dakinevich <jan.dakinevich@gmail.com> Tested-by:
Ladi Prosek <lprosek@redhat.com> Signed-off-by:
Radim Krčmář <rkrcmar@redhat.com>
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Jan Dakinevich authored
- Remove VMX_EPT_EXTENT_INDIVIDUAL_ADDR, since there is no such type of EPT invalidation - Add missing VPID types names Signed-off-by:
Jan Dakinevich <jan.dakinevich@gmail.com> Tested-by:
Ladi Prosek <lprosek@redhat.com> Signed-off-by:
Radim Krčmář <rkrcmar@redhat.com>
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Jim Mattson authored
From the Intel SDM, volume 3, section 10.4.3, "Enabling or Disabling the Local APIC," When IA32_APIC_BASE[11] is 0, the processor is functionally equivalent to an IA-32 processor without an on-chip APIC. The CPUID feature flag for the APIC (see Section 10.4.2, "Presence of the Local APIC") is also set to 0. Signed-off-by:
Jim Mattson <jmattson@google.com> [Changed subject tag from nVMX to x86.] Signed-off-by:
Radim Krčmář <rkrcmar@redhat.com>
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