- 16 May, 2022 3 commits
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Marc Zyngier authored
* kvm-arm64/psci-suspend: : . : Add support for PSCI SYSTEM_SUSPEND and allow userspace to : filter the wake-up events. : : Patches courtesy of Oliver. : . Documentation: KVM: Fix title level for PSCI_SUSPEND selftests: KVM: Test SYSTEM_SUSPEND PSCI call selftests: KVM: Refactor psci_test to make it amenable to new tests selftests: KVM: Use KVM_SET_MP_STATE to power off vCPU in psci_test selftests: KVM: Create helper for making SMCCC calls selftests: KVM: Rename psci_cpu_on_test to psci_test KVM: arm64: Implement PSCI SYSTEM_SUSPEND KVM: arm64: Add support for userspace to suspend a vCPU KVM: arm64: Return a value from check_vcpu_requests() KVM: arm64: Rename the KVM_REQ_SLEEP handler KVM: arm64: Track vCPU power state using MP state values KVM: arm64: Dedupe vCPU power off helpers KVM: arm64: Don't depend on fallthrough to hide SYSTEM_RESET2 Signed-off-by:Marc Zyngier <maz@kernel.org>
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Marc Zyngier authored
* kvm-arm64/hcall-selection: : . : Introduce a new set of virtual sysregs for userspace to : select the hypercalls it wants to see exposed to the guest. : : Patches courtesy of Raghavendra and Oliver. : . KVM: arm64: Fix hypercall bitmap writeback when vcpus have already run KVM: arm64: Hide KVM_REG_ARM_*_BMAP_BIT_COUNT from userspace Documentation: Fix index.rst after psci.rst renaming selftests: KVM: aarch64: Add the bitmap firmware registers to get-reg-list selftests: KVM: aarch64: Introduce hypercall ABI test selftests: KVM: Create helper for making SMCCC calls selftests: KVM: Rename psci_cpu_on_test to psci_test tools: Import ARM SMCCC definitions Docs: KVM: Add doc for the bitmap firmware registers Docs: KVM: Rename psci.rst to hypercalls.rst KVM: arm64: Add vendor hypervisor firmware register KVM: arm64: Add standard hypervisor firmware register KVM: arm64: Setup a framework for hypercall bitmap firmware registers KVM: arm64: Factor out firmware register handling from psci.c Signed-off-by: -
Marc Zyngier authored
We generally want to disallow hypercall bitmaps being changed once vcpus have already run. But we must allow the write if the written value is unchanged so that userspace can rewrite the register file on reboot, for example. Without this, a QEMU-based VM will fail to reboot correctly. The original code was correct, and it is me that introduced the regression. Fixes: 05714cab ("KVM: arm64: Setup a framework for hypercall bitmap firmware registers") Signed-off-by:
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- 15 May, 2022 1 commit
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Marc Zyngier authored
These constants will change over time, and userspace has no business knowing about them. Hide them behind __KERNEL__. Signed-off-by:
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- 05 May, 2022 1 commit
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Stephen Rothwell authored
The htmldoc build breaks in a funny way with: <quote> Sphinx parallel build error: docutils.utils.SystemMessage: /home/sfr/next/next/Documentation/virt/kvm/api.rst:6175: (SEVERE/4) Title level inconsistent: For arm/arm64: ^^^^^^^^^^^^^^ </quote> Swap the ^^s for a bunch of --s... Signed-off-by:
Stephen Rothwell <sfr@canb.auug.org.au> [maz: commit message] Signed-off-by:
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- 04 May, 2022 18 commits
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Marc Zyngier authored
Fix the TOC in index.rst after psci.rst has been renamed to hypercalls.rst. Signed-off-by:
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Marc Zyngier authored
* kvm-arm64/aarch32-idreg-trap: : . : Add trapping/sanitising infrastructure for AArch32 systen registers, : allowing more control over what we actually expose (such as the PMU). : : Patches courtesy of Oliver and Alexandru. : . KVM: arm64: Fix new instances of 32bit ESRs KVM: arm64: Hide AArch32 PMU registers when not available KVM: arm64: Start trapping ID registers for 32 bit guests KVM: arm64: Plumb cp10 ID traps through the AArch64 sysreg handler KVM: arm64: Wire up CP15 feature registers to their AArch64 equivalents KVM: arm64: Don't write to Rt unless sys_reg emulation succeeds KVM: arm64: Return a bool from emulate_cp() Signed-off-by: -
Marc Zyngier authored
* kvm-arm64/hyp-stack-guard: : . : Harden the EL2 stack by providing stack guards, courtesy of : Kalesh Singh. : . KVM: arm64: Symbolize the nVHE HYP addresses KVM: arm64: Detect and handle hypervisor stack overflows KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack KVM: arm64: Add guard pages for KVM nVHE hypervisor stack KVM: arm64: Introduce pkvm_alloc_private_va_range() KVM: arm64: Introduce hyp_alloc_private_va_range() Signed-off-by: -
Marc Zyngier authored
* kvm-arm64/wfxt: : . : Add support for the WFET/WFIT instructions that provide the same : service as WFE/WFI, only with a timeout. : . KVM: arm64: Expose the WFXT feature to guests KVM: arm64: Offer early resume for non-blocking WFxT instructions KVM: arm64: Handle blocking WFIT instruction KVM: arm64: Introduce kvm_counter_compute_delta() helper KVM: arm64: Simplify kvm_cpu_has_pending_timer() arm64: Use WFxT for __delay() when possible arm64: Add wfet()/wfit() helpers arm64: Add HWCAP advertising FEAT_WFXT arm64: Add RV and RN fields for ESR_ELx_WFx_ISS arm64: Expand ESR_ELx_WFx_ISS_TI to match its ARMv8.7 definition Signed-off-by: -
Marc Zyngier authored
Merge arm64's SME branch to resolve conflicts with the WFxT branch. Signed-off-by: -
Oliver Upton authored
Assert that the vCPU exits to userspace with KVM_SYSTEM_EVENT_SUSPEND if the guest calls PSCI SYSTEM_SUSPEND. Additionally, guarantee that the SMC32 and SMC64 flavors of this call are discoverable with the PSCI_FEATURES call. Signed-off-by:
Oliver Upton <oupton@google.com> Signed-off-by:
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Oliver Upton authored
Split up the current test into several helpers that will be useful to subsequent test cases added to the PSCI test suite. Signed-off-by:
Andrew Jones <drjones@redhat.com> Signed-off-by:
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Oliver Upton authored
Setting a vCPU's MP state to KVM_MP_STATE_STOPPED has the effect of powering off the vCPU. Rather than using the vCPU init feature flag, use the KVM_SET_MP_STATE ioctl to power off the target vCPU. Signed-off-by:
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Oliver Upton authored
The PSCI and PV stolen time tests both need to make SMCCC calls within the guest. Create a helper for making SMCCC calls and rework the existing tests to use the library function. Signed-off-by:
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Oliver Upton authored
There are other interactions with PSCI worth testing; rename the PSCI test to make it more generic. No functional change intended. Signed-off-by:
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Oliver Upton authored
ARM DEN0022D.b 5.19 "SYSTEM_SUSPEND" describes a PSCI call that allows software to request that a system be placed in the deepest possible low-power state. Effectively, software can use this to suspend itself to RAM. Unfortunately, there really is no good way to implement a system-wide PSCI call in KVM. Any precondition checks done in the kernel will need to be repeated by userspace since there is no good way to protect a critical section that spans an exit to userspace. SYSTEM_RESET and SYSTEM_OFF are equally plagued by this issue, although no users have seemingly cared for the relatively long time these calls have been supported. The solution is to just make the whole implementation userspace's problem. Introduce a new system event, KVM_SYSTEM_EVENT_SUSPEND, that indicates to userspace a calling vCPU has invoked PSCI SYSTEM_SUSPEND. Additionally, add a CAP to get buy-in from userspace for this new exit type. Only advertise the SYSTEM_SUSPEND PSCI call if userspace has opted in. If a vCPU calls SYSTEM_SUSPEND, punt straight to userspace. Provide explicit documentation of userspace's responsibilites for the exit and point to the PSCI specification to describe the actual PSCI call. Reviewed-by:
Reiji Watanabe <reijiw@google.com> Signed-off-by:
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Oliver Upton authored
Introduce a new MP state, KVM_MP_STATE_SUSPENDED, which indicates a vCPU is in a suspended state. In the suspended state the vCPU will block until a wakeup event (pending interrupt) is recognized. Add a new system event type, KVM_SYSTEM_EVENT_WAKEUP, to indicate to userspace that KVM has recognized one such wakeup event. It is the responsibility of userspace to then make the vCPU runnable, or leave it suspended until the next wakeup event. Signed-off-by:
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Oliver Upton authored
A subsequent change to KVM will introduce a vCPU request that could result in an exit to userspace. Change check_vcpu_requests() to return a value and document the function. Unconditionally return 1 for now. Signed-off-by:
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Oliver Upton authored
The naming of the kvm_req_sleep function is confusing: the function itself sleeps the vCPU, it does not request such an event. Rename the function to make its purpose more clear. No functional change intended. Signed-off-by:
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Oliver Upton authored
A subsequent change to KVM will add support for additional power states. Store the MP state by value rather than keeping track of it as a boolean. No functional change intended. Signed-off-by:
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Oliver Upton authored
vcpu_power_off() and kvm_psci_vcpu_off() are equivalent; rename the former and replace all callsites to the latter. No functional change intended. Signed-off-by:
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Oliver Upton authored
Depending on a fallthrough to the default case for hiding SYSTEM_RESET2 requires that any new case statements clean up the failure path for this PSCI call. Unhitch SYSTEM_RESET2 from the default case by setting val to PSCI_RET_NOT_SUPPORTED outside of the switch statement. Apply the cleanup to both the PSCI_1_1_FN_SYSTEM_RESET2 and PSCI_1_0_FN_PSCI_FEATURES handlers. No functional change intended. Signed-off-by:
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Marc Zyngier authored
Fix the new instances of ESR being described as a u32, now that we consistently are using a u64 for this register. Signed-off-by:
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- 03 May, 2022 17 commits
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Raghavendra Rao Ananta authored
Add the psuedo-firmware registers KVM_REG_ARM_STD_BMAP, KVM_REG_ARM_STD_HYP_BMAP, and KVM_REG_ARM_VENDOR_HYP_BMAP to the base_regs[] list. Also, add the COPROC support for KVM_REG_ARM_FW_FEAT_BMAP. Signed-off-by:
Raghavendra Rao Ananta <rananta@google.com> Signed-off-by:
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Raghavendra Rao Ananta authored
Introduce a KVM selftest to check the hypercall interface for arm64 platforms. The test validates the user-space' [GET|SET]_ONE_REG interface to read/write the psuedo-firmware registers as well as its effects on the guest upon certain configurations. Signed-off-by:
Gavin Shan <gshan@redhat.com> Signed-off-by:
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Oliver Upton authored
The PSCI and PV stolen time tests both need to make SMCCC calls within the guest. Create a helper for making SMCCC calls and rework the existing tests to use the library function. Signed-off-by:
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Oliver Upton authored
There are other interactions with PSCI worth testing; rename the PSCI test to make it more generic. No functional change intended. Signed-off-by:
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Raghavendra Rao Ananta authored
Import the standard SMCCC definitions from include/linux/arm-smccc.h. Signed-off-by:
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Raghavendra Rao Ananta authored
Add the documentation for the bitmap firmware registers in hypercalls.rst and api.rst. This includes the details for KVM_REG_ARM_STD_BMAP, KVM_REG_ARM_STD_HYP_BMAP, and KVM_REG_ARM_VENDOR_HYP_BMAP registers. Since the document is growing to carry other hypercall related information, make necessary adjustments to present the document in a generic sense, rather than being PSCI focused. Signed-off-by:
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Raghavendra Rao Ananta authored
Since the doc also covers general hypercalls' details, rather than just PSCI, and the fact that the bitmap firmware registers' details will be added to this doc, rename the file to a more appropriate name- hypercalls.rst. Signed-off-by:
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Raghavendra Rao Ananta authored
Introduce the firmware register to hold the vendor specific hypervisor service calls (owner value 6) as a bitmap. The bitmap represents the features that'll be enabled for the guest, as configured by the user-space. Currently, this includes support for KVM-vendor features along with reading the UID, represented by bit-0, and Precision Time Protocol (PTP), represented by bit-1. Signed-off-by:
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Raghavendra Rao Ananta authored
Introduce the firmware register to hold the standard hypervisor service calls (owner value 5) as a bitmap. The bitmap represents the features that'll be enabled for the guest, as configured by the user-space. Currently, this includes support only for Paravirtualized time, represented by bit-0. Signed-off-by:
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Raghavendra Rao Ananta authored
KVM regularly introduces new hypercall services to the guests without any consent from the userspace. This means, the guests can observe hypercall services in and out as they migrate across various host kernel versions. This could be a major problem if the guest discovered a hypercall, started using it, and after getting migrated to an older kernel realizes that it's no longer available. Depending on how the guest handles the change, there's a potential chance that the guest would just panic. As a result, there's a need for the userspace to elect the services that it wishes the guest to discover. It can elect these services based on the kernels spread across its (migration) fleet. To remedy this, extend the existing firmware pseudo-registers, such as KVM_REG_ARM_PSCI_VERSION, but by creating a new COPROC register space for all the hypercall services available. These firmware registers are categorized based on the service call owners, but unlike the existing firmware pseudo-registers, they hold the features supported in the form of a bitmap. During the VM initialization, the registers are set to upper-limit of the features supported by the corresponding registers. It's expected that the VMMs discover the features provided by each register via GET_ONE_REG, and write back the desired values using SET_ONE_REG. KVM allows this modification only until the VM has started. Some of the standard features are not mapped to any bits of the registers. But since they can recreate the original problem of making it available without userspace's consent, they need to be explicitly added to the case-list in kvm_hvc_call_default_allowed(). Any function-id that's not enabled via the bitmap, or not listed in kvm_hvc_call_default_allowed, will be returned as SMCCC_RET_NOT_SUPPORTED to the guest. Older userspace code can simply ignore the feature and the hypercall services will be exposed unconditionally to the guests, thus ensuring backward compatibility. In this patch, the framework adds the register only for ARM's standard secure services (owner value 4). Currently, this includes support only for ARM True Random Number Generator (TRNG) service, with bit-0 of the register representing mandatory features of v1.0. Other services are momentarily added in the upcoming patches. Signed-off-by:
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Raghavendra Rao Ananta authored
Common hypercall firmware register handing is currently employed by psci.c. Since the upcoming patches add more of these registers, it's better to move the generic handling to hypercall.c for a cleaner presentation. While we are at it, collect all the firmware registers under fw_reg_ids[] to help implement kvm_arm_get_fw_num_regs() and kvm_arm_copy_fw_reg_indices() in a generic way. Also, define KVM_REG_FEATURE_LEVEL_MASK using a GENMASK instead. No functional change intended. Signed-off-by:
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Alexandru Elisei authored
commit 11663111 ("KVM: arm64: Hide PMU registers from userspace when not available") hid the AArch64 PMU registers from userspace and guest when the PMU VCPU feature was not set. Do the same when the PMU registers are accessed by an AArch32 guest. While we're at it, rename the previously unused AA32_ZEROHIGH to AA32_DIRECT to match the behavior of get_access_mask(). Now that KVM emulates ID_DFR0 and hides the PMU from the guest when the feature is not set, it is safe to inject to inject an undefined exception when the PMU is not present, as that corresponds to the architected behaviour. Signed-off-by:
Alexandru Elisei <alexandru.elisei@arm.com> [Oliver - Add AA32_DIRECT to match the zero value of the enum] Signed-off-by:
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Oliver Upton authored
To date KVM has not trapped ID register accesses from AArch32, meaning that guests get an unconstrained view of what hardware supports. This can be a serious problem because we try to base the guest's feature registers on values that are safe system-wide. Furthermore, KVM does not implement the latest ISA in the PMU and Debug architecture, so we constrain these fields to supported values. Since KVM now correctly handles CP15 and CP10 register traps, we no longer need to clear HCR_EL2.TID3 for 32 bit guests and will instead emulate reads with their safe values. Signed-off-by:
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Oliver Upton authored
In order to enable HCR_EL2.TID3 for AArch32 guests KVM needs to handle traps where ESR_EL2.EC=0x8, which corresponds to an attempted VMRS access from an ID group register. Specifically, the MVFR{0-2} registers are accessed this way from AArch32. Conveniently, these registers are architecturally mapped to MVFR{0-2}_EL1 in AArch64. Furthermore, KVM already handles reads to these aliases in AArch64. Plumb VMRS read traps through to the general AArch64 system register handler. Signed-off-by: -
Oliver Upton authored
KVM currently does not trap ID register accesses from an AArch32 EL1. This is painful for a couple of reasons. Certain unimplemented features are visible to AArch32 EL1, as we limit PMU to version 3 and the debug architecture to v8.0. Additionally, we attempt to paper over heterogeneous systems by using register values that are safe system-wide. All this hard work is completely sidestepped because KVM does not set TID3 for AArch32 guests. Fix up handling of CP15 feature registers by simply rerouting to their AArch64 aliases. Punt setting HCR_EL2.TID3 to a later change, as we need to fix up the oddball CP10 feature registers still. Signed-off-by:
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Oliver Upton authored
emulate_sys_reg() returns 1 unconditionally, even though a a system register access can fail. Furthermore, kvm_handle_sys_reg() writes to Rt for every register read, regardless of if it actually succeeded. Though this pattern is safe (as params.regval is initialized with the current value of Rt) it is a bit ugly. Indicate failure if the register access could not be emulated and only write to Rt on success. Signed-off-by:
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Oliver Upton authored
KVM indicates success/failure in several ways, but generally an integer is used when conditionally bouncing to userspace is involved. That is not the case from emulate_cp(); just use a bool instead. No functional change intended. Signed-off-by:
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