kernel.git/arch/arm64/kvm, branch linux-5.12.y

KVM: arm64: Don't zero the cycle count register when PMCR_EL0.P is set

2021-07-14T14:59:37Z

[ Upstream commit 2a71fabf6a1bc9162a84e18d6ab991230ca4d588 ] According to ARM DDI 0487G.a, page D13-3895, setting the PMCR_EL0.P bit to 1 has the following effect: "Reset all event counters accessible in the current Exception level, not including PMCCNTR_EL0, to zero." Similar behaviour is described for AArch32 on page G8-7022. Make it so. Fixes: c01d6a18023b ("KVM: arm64: pmu: Only handle supported event counters") Signed-off-by: Alexandru Elisei Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210618105139.83795-1-alexandru.elisei@arm.com Signed-off-by: Sasha Levin

KVM: arm64: Restore PMU configuration on first run

2021-07-14T14:59:21Z

[ Upstream commit d0c94c49792cf780cbfefe29f81bb8c3b73bc76b ] Restoring a guest with an active virtual PMU results in no perf counters being instanciated on the host side. Not quite what you'd expect from a restore. In order to fix this, force a writeback of PMCR_EL0 on the first run of a vcpu (using a new request so that it happens once the vcpu has been loaded). This will in turn create all the host-side counters that were missing. Reported-by: Jinank Jain Tested-by: Jinank Jain Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/87wnrbylxv.wl-maz@kernel.org Link: https://lore.kernel.org/r/b53dfcf9bbc4db7f96154b1cd5188d72b9766358.camel@amazon.de Signed-off-by: Sasha Levin

KVM: arm64: Resolve all pending PC updates before immediate exit

2021-06-10T11:41:48Z

commit e3e880bb1518eb10a4b4bb4344ed614d6856f190 upstream. Commit 26778aaa134a ("KVM: arm64: Commit pending PC adjustemnts before returning to userspace") fixed the PC updating issue by forcing an explicit synchronisation of the exception state on vcpu exit to userspace. However, we forgot to take into account the case where immediate_exit is set by userspace and KVM_RUN will exit immediately. Fix it by resolving all pending PC updates before returning to userspace. Since __kvm_adjust_pc() relies on a loaded vcpu context, I moved the immediate_exit checking right after vcpu_load(). We will get some overhead if immediate_exit is true (which should hopefully be rare). Fixes: 26778aaa134a ("KVM: arm64: Commit pending PC adjustemnts before returning to userspace") Signed-off-by: Zenghui Yu Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210526141831.1662-1-yuzenghui@huawei.com Cc: stable@vger.kernel.org # 5.11 [yuz: stable-5.12.y backport] Signed-off-by: Zenghui Yu Reviewed-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman

KVM: arm64: Commit pending PC adjustemnts before returning to userspace

2021-06-10T11:41:48Z

commit 26778aaa134a9aefdf5dbaad904054d7be9d656d upstream. KVM currently updates PC (and the corresponding exception state) using a two phase approach: first by setting a set of flags, then by converting these flags into a state update when the vcpu is about to enter the guest. However, this creates a disconnect with userspace if the vcpu thread returns there with any exception/PC flag set. In this case, the exposed context is wrong, as userspace doesn't have access to these flags (they aren't architectural). It also means that these flags are preserved across a reset, which isn't expected. To solve this problem, force an explicit synchronisation of the exception state on vcpu exit to userspace. As an optimisation for nVHE systems, only perform this when there is something pending. Reported-by: Zenghui Yu Reviewed-by: Alexandru Elisei Reviewed-by: Zenghui Yu Tested-by: Zenghui Yu Signed-off-by: Marc Zyngier Cc: stable@vger.kernel.org # 5.11 [yuz: stable-5.12.y backport: allocate a new number (15) for __KVM_HOST_SMCCC_FUNC___kvm_adjust_pc to keep the host_hcall array tightly packed] Signed-off-by: Zenghui Yu Reviewed-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman

KVM: arm64: Prevent mixed-width VM creation

2021-06-03T07:09:29Z

commit 66e94d5cafd4decd4f92d16a022ea587d7f4094f upstream. It looks like we have tolerated creating mixed-width VMs since... forever. However, that was never the intention, and we'd rather not have to support that pointless complexity. Forbid such a setup by making sure all the vcpus have the same register width. Reported-by: Steven Price Signed-off-by: Marc Zyngier Cc: stable@vger.kernel.org Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20210524170752.1549797-1-maz@kernel.org Signed-off-by: Greg Kroah-Hartman

KVM: arm64: Fix debug register indexing

2021-06-03T07:09:29Z

commit cb853ded1d25e5b026ce115dbcde69e3d7e2e831 upstream. Commit 03fdfb2690099 ("KVM: arm64: Don't write junk to sysregs on reset") flipped the register number to 0 for all the debug registers in the sysreg table, hereby indicating that these registers live in a separate shadow structure. However, the author of this patch failed to realise that all the accessors are using that particular index instead of the register encoding, resulting in all the registers hitting index 0. Not quite a valid implementation of the architecture... Address the issue by fixing all the accessors to use the CRm field of the encoding, which contains the debug register index. Fixes: 03fdfb2690099 ("KVM: arm64: Don't write junk to sysregs on reset") Reported-by: Ricardo Koller Signed-off-by: Marc Zyngier Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

KVM: arm64: Move __adjust_pc out of line

2021-06-03T07:09:29Z

commit f5e30680616ab09e690b153b7a68ff7dd13e6579 upstream. In order to make it easy to call __adjust_pc() from the EL1 code (in the case of nVHE), rename it to __kvm_adjust_pc() and move it out of line. No expected functional change. Reviewed-by: Alexandru Elisei Reviewed-by: Zenghui Yu Tested-by: Zenghui Yu Signed-off-by: Marc Zyngier Cc: stable@vger.kernel.org # 5.11 Signed-off-by: Greg Kroah-Hartman

KVM: arm64: Initialize VCPU mdcr_el2 before loading it

2021-05-14T08:52:49Z

[ Upstream commit 263d6287da1433aba11c5b4046388f2cdf49675c ] When a VCPU is created, the kvm_vcpu struct is initialized to zero in kvm_vm_ioctl_create_vcpu(). On VHE systems, the first time vcpu.arch.mdcr_el2 is loaded on hardware is in vcpu_load(), before it is set to a sensible value in kvm_arm_setup_debug() later in the run loop. The result is that KVM executes for a short time with MDCR_EL2 set to zero. This has several unintended consequences: * Setting MDCR_EL2.HPMN to 0 is constrained unpredictable according to ARM DDI 0487G.a, page D13-3820. The behavior specified by the architecture in this case is for the PE to behave as if MDCR_EL2.HPMN is set to a value less than or equal to PMCR_EL0.N, which means that an unknown number of counters are now disabled by MDCR_EL2.HPME, which is zero. * The host configuration for the other debug features controlled by MDCR_EL2 is temporarily lost. This has been harmless so far, as Linux doesn't use the other fields, but that might change in the future. Let's avoid both issues by initializing the VCPU's mdcr_el2 field in kvm_vcpu_vcpu_first_run_init(), thus making sure that the MDCR_EL2 register has a consistent value after each vcpu_load(). Fixes: d5a21bcc2995 ("KVM: arm64: Move common VHE/non-VHE trap config in separate functions") Signed-off-by: Alexandru Elisei Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210407144857.199746-3-alexandru.elisei@arm.com Signed-off-by: Sasha Levin

KVM: arm64: Fix error return code in init_hyp_mode()

2021-05-14T08:52:48Z

[ Upstream commit 52b9e265d22bccc5843e167da76ab119874e2883 ] Fix to return a negative error code from the error handling case instead of 0, as done elsewhere in this function. Fixes: eeeee7193df0 ("KVM: arm64: Bootstrap PSCI SMC handler in nVHE EL2") Reported-by: Hulk Robot Signed-off-by: Wang Wensheng Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210406121759.5407-1-wangwensheng4@huawei.com Signed-off-by: Sasha Levin

KVM: arm64: Fix KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION read

2021-05-14T08:52:13Z

commit 53b16dd6ba5cf64ed147ac3523ec34651d553cb0 upstream. The doc says: "The characteristics of a specific redistributor region can be read by presetting the index field in the attr data. Only valid for KVM_DEV_TYPE_ARM_VGIC_V3" Unfortunately the existing code fails to read the input attr data. Fixes: 04c110932225 ("KVM: arm/arm64: Implement KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION") Cc: stable@vger.kernel.org#v4.17+ Signed-off-by: Eric Auger Reviewed-by: Alexandru Elisei Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210405163941.510258-3-eric.auger@redhat.com Signed-off-by: Greg Kroah-Hartman