From fb0fd2ce38400e158f3eb483b0f1c553d3551445 Mon Sep 17 00:00:00 2001 From: Joao Martins Date: Mon, 18 Jun 2018 12:17:42 -0400 Subject: [PATCH] i386/xen: implement HYPERVISOR_memory_op Specifically XENMEM_add_to_physmap with space XENMAPSPACE_shared_info to allow the guest to set its shared_info page. Signed-off-by: Joao Martins [dwmw2: Use the xen_overlay device, add compat support] Signed-off-by: David Woodhouse Reviewed-by: Paul Durrant --- target/i386/kvm/trace-events | 1 + target/i386/kvm/xen-compat.h | 27 ++++++++++ target/i386/kvm/xen-emu.c | 116 ++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 143 insertions(+), 1 deletion(-) create mode 100644 target/i386/kvm/xen-compat.h diff --git a/target/i386/kvm/trace-events b/target/i386/kvm/trace-events index bb732e1da8..8e9f269f56 100644 --- a/target/i386/kvm/trace-events +++ b/target/i386/kvm/trace-events @@ -9,3 +9,4 @@ kvm_x86_update_msi_routes(int num) "Updated %d MSI routes" # xen-emu.c kvm_xen_hypercall(int cpu, uint8_t cpl, uint64_t input, uint64_t a0, uint64_t a1, uint64_t a2, uint64_t ret) "xen_hypercall: cpu %d cpl %d input %" PRIu64 " a0 0x%" PRIx64 " a1 0x%" PRIx64 " a2 0x%" PRIx64" ret 0x%" PRIx64 kvm_xen_soft_reset(void) "" +kvm_xen_set_shared_info(uint64_t gfn) "shared info at gfn 0x%" PRIx64 diff --git a/target/i386/kvm/xen-compat.h b/target/i386/kvm/xen-compat.h new file mode 100644 index 0000000000..2d852e2a28 --- /dev/null +++ b/target/i386/kvm/xen-compat.h @@ -0,0 +1,27 @@ +/* + * Xen HVM emulation support in KVM + * + * Copyright © 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved. + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + * + */ + +#ifndef QEMU_I386_KVM_XEN_COMPAT_H +#define QEMU_I386_KVM_XEN_COMPAT_H + +#include "hw/xen/interface/memory.h" + +typedef uint32_t compat_pfn_t; +typedef uint32_t compat_ulong_t; + +struct compat_xen_add_to_physmap { + domid_t domid; + uint16_t size; + unsigned int space; + compat_ulong_t idx; + compat_pfn_t gpfn; +}; + +#endif /* QEMU_I386_XEN_COMPAT_H */ diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c index be6d85f2cb..5d79827128 100644 --- a/target/i386/kvm/xen-emu.c +++ b/target/i386/kvm/xen-emu.c @@ -12,6 +12,7 @@ #include "qemu/osdep.h" #include "qemu/log.h" #include "qemu/main-loop.h" +#include "hw/xen/xen.h" #include "sysemu/kvm_int.h" #include "sysemu/kvm_xen.h" #include "kvm/kvm_i386.h" @@ -24,6 +25,15 @@ #include "hw/xen/interface/version.h" #include "hw/xen/interface/sched.h" +#include "hw/xen/interface/memory.h" + +#include "xen-compat.h" + +#ifdef TARGET_X86_64 +#define hypercall_compat32(longmode) (!(longmode)) +#else +#define hypercall_compat32(longmode) (false) +#endif static int kvm_gva_rw(CPUState *cs, uint64_t gva, void *_buf, size_t sz, bool is_write) @@ -175,13 +185,114 @@ static bool kvm_xen_hcall_xen_version(struct kvm_xen_exit *exit, X86CPU *cpu, return true; } +static int xen_set_shared_info(uint64_t gfn) +{ + uint64_t gpa = gfn << TARGET_PAGE_BITS; + int err; + + QEMU_IOTHREAD_LOCK_GUARD(); + + /* + * The xen_overlay device tells KVM about it too, since it had to + * do that on migration load anyway (unless we're going to jump + * through lots of hoops to maintain the fiction that this isn't + * KVM-specific. + */ + err = xen_overlay_map_shinfo_page(gpa); + if (err) { + return err; + } + + trace_kvm_xen_set_shared_info(gfn); + + return err; +} + +static int add_to_physmap_one(uint32_t space, uint64_t idx, uint64_t gfn) +{ + switch (space) { + case XENMAPSPACE_shared_info: + if (idx > 0) { + return -EINVAL; + } + return xen_set_shared_info(gfn); + + case XENMAPSPACE_grant_table: + case XENMAPSPACE_gmfn: + case XENMAPSPACE_gmfn_range: + return -ENOTSUP; + + case XENMAPSPACE_gmfn_foreign: + case XENMAPSPACE_dev_mmio: + return -EPERM; + + default: + return -EINVAL; + } +} + +static int do_add_to_physmap(struct kvm_xen_exit *exit, X86CPU *cpu, + uint64_t arg) +{ + struct xen_add_to_physmap xatp; + CPUState *cs = CPU(cpu); + + if (hypercall_compat32(exit->u.hcall.longmode)) { + struct compat_xen_add_to_physmap xatp32; + + qemu_build_assert(sizeof(struct compat_xen_add_to_physmap) == 16); + if (kvm_copy_from_gva(cs, arg, &xatp32, sizeof(xatp32))) { + return -EFAULT; + } + xatp.domid = xatp32.domid; + xatp.size = xatp32.size; + xatp.space = xatp32.space; + xatp.idx = xatp32.idx; + xatp.gpfn = xatp32.gpfn; + } else { + if (kvm_copy_from_gva(cs, arg, &xatp, sizeof(xatp))) { + return -EFAULT; + } + } + + if (xatp.domid != DOMID_SELF && xatp.domid != xen_domid) { + return -ESRCH; + } + + return add_to_physmap_one(xatp.space, xatp.idx, xatp.gpfn); +} + +static bool kvm_xen_hcall_memory_op(struct kvm_xen_exit *exit, X86CPU *cpu, + int cmd, uint64_t arg) +{ + int err; + + switch (cmd) { + case XENMEM_add_to_physmap: + err = do_add_to_physmap(exit, cpu, arg); + break; + + default: + return false; + } + + exit->u.hcall.result = err; + return true; +} + int kvm_xen_soft_reset(void) { + int err; + assert(qemu_mutex_iothread_locked()); trace_kvm_xen_soft_reset(); - /* Nothing to reset... yet. */ + err = xen_overlay_map_shinfo_page(INVALID_GFN); + if (err) { + return err; + } + return 0; } @@ -270,6 +381,9 @@ static bool do_kvm_xen_handle_exit(X86CPU *cpu, struct kvm_xen_exit *exit) case __HYPERVISOR_sched_op: return kvm_xen_hcall_sched_op(exit, cpu, exit->u.hcall.params[0], exit->u.hcall.params[1]); + case __HYPERVISOR_memory_op: + return kvm_xen_hcall_memory_op(exit, cpu, exit->u.hcall.params[0], + exit->u.hcall.params[1]); case __HYPERVISOR_xen_version: return kvm_xen_hcall_xen_version(exit, cpu, exit->u.hcall.params[0], exit->u.hcall.params[1]); -- 2.11.0