diff options
| author | Metin Kaya <metikaya@amazon.com> | 2022-03-21 11:05:32 +0000 |
|---|---|---|
| committer | David Woodhouse <dwmw@amazon.co.uk> | 2022-11-30 19:24:56 +0000 |
| commit | 214b0a88c46d5f32d80abe0d1bc2eea1cbd38f11 (patch) | |
| tree | d8a88db46573406a8be2a144e38f000eb2e6bce5 | |
| parent | df0bb47baa95aad133820b149851d5b94cbc6790 (diff) | |
KVM: x86/xen: add support for 32-bit guests in SCHEDOP_poll
This patch introduces compat version of struct sched_poll for
SCHEDOP_poll sub-operation of sched_op hypercall, reads correct amount
of data (16 bytes in 32-bit case, 24 bytes otherwise) by using new
compat_sched_poll struct, copies it to sched_poll properly, and lets
rest of the code run as is.
Signed-off-by: Metin Kaya <metikaya@amazon.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
| -rw-r--r-- | arch/x86/kvm/xen.c | 33 | ||||
| -rw-r--r-- | arch/x86/kvm/xen.h | 7 |
2 files changed, 36 insertions, 4 deletions
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c index 9187d024d006..3e434dc339fb 100644 --- a/arch/x86/kvm/xen.c +++ b/arch/x86/kvm/xen.c @@ -1201,20 +1201,45 @@ static bool kvm_xen_schedop_poll(struct kvm_vcpu *vcpu, bool longmode, evtchn_port_t port, *ports; gpa_t gpa; - if (!longmode || !lapic_in_kernel(vcpu) || + if (!lapic_in_kernel(vcpu) || !(vcpu->kvm->arch.xen_hvm_config.flags & KVM_XEN_HVM_CONFIG_EVTCHN_SEND)) return false; idx = srcu_read_lock(&vcpu->kvm->srcu); gpa = kvm_mmu_gva_to_gpa_system(vcpu, param, NULL); srcu_read_unlock(&vcpu->kvm->srcu, idx); - - if (!gpa || kvm_vcpu_read_guest(vcpu, gpa, &sched_poll, - sizeof(sched_poll))) { + if (!gpa) { *r = -EFAULT; return true; } + if (IS_ENABLED(CONFIG_64BIT) && !longmode) { + struct compat_sched_poll sp32; + + /* Sanity check that the compat struct definition is correct */ + BUILD_BUG_ON(sizeof(sp32) != 16); + + if (kvm_vcpu_read_guest(vcpu, gpa, &sp32, sizeof(sp32))) { + *r = -EFAULT; + return true; + } + + /* + * This is a 32-bit pointer to an array of evtchn_port_t which + * are uint32_t, so once it's converted no further compat + * handling is needed. + */ + sched_poll.ports = (void *)(unsigned long)(sp32.ports); + sched_poll.nr_ports = sp32.nr_ports; + sched_poll.timeout = sp32.timeout; + } else { + if (kvm_vcpu_read_guest(vcpu, gpa, &sched_poll, + sizeof(sched_poll))) { + *r = -EFAULT; + return true; + } + } + if (unlikely(sched_poll.nr_ports > 1)) { /* Xen (unofficially) limits number of pollers to 128 */ if (sched_poll.nr_ports > 128) { diff --git a/arch/x86/kvm/xen.h b/arch/x86/kvm/xen.h index 8503d2c6891e..ea33d80a0c51 100644 --- a/arch/x86/kvm/xen.h +++ b/arch/x86/kvm/xen.h @@ -207,4 +207,11 @@ struct compat_vcpu_runstate_info { uint64_t time[4]; } __attribute__((packed)); +struct compat_sched_poll { + /* This is actually a guest virtual address which points to ports. */ + uint32_t ports; + unsigned int nr_ports; + uint64_t timeout; +}; + #endif /* __ARCH_X86_KVM_XEN_H__ */ |