From 8b57d5c523f8f1a650188ffa58939e1c5aaa6254 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Tue, 27 Dec 2022 19:02:23 +0000 Subject: [PATCH] i386/xen: Reserve Xen special pages for console, xenstore rings Xen has eight frames at 0xfeff8000 for this; we only really need two for now and KVM puts the identity map at 0xfeffc000, so limit ourselves to four. Signed-off-by: David Woodhouse Reviewed-by: Paul Durrant --- include/sysemu/kvm_xen.h | 9 +++++++++ target/i386/kvm/xen-emu.c | 10 ++++++++++ 2 files changed, 19 insertions(+) diff --git a/include/sysemu/kvm_xen.h b/include/sysemu/kvm_xen.h index 49afa0eb9e..b2aafaf7ab 100644 --- a/include/sysemu/kvm_xen.h +++ b/include/sysemu/kvm_xen.h @@ -30,4 +30,13 @@ uint16_t kvm_xen_get_gnttab_max_frames(void); #define kvm_xen_has_cap(cap) (!!(kvm_xen_get_caps() & \ KVM_XEN_HVM_CONFIG_ ## cap)) +#define XEN_SPECIAL_AREA_ADDR 0xfeff8000UL +#define XEN_SPECIAL_AREA_SIZE 0x4000UL + +#define XEN_SPECIALPAGE_CONSOLE 0 +#define XEN_SPECIALPAGE_XENSTORE 1 + +#define XEN_SPECIAL_PFN(x) ((XEN_SPECIAL_AREA_ADDR >> TARGET_PAGE_BITS) + \ + XEN_SPECIALPAGE_##x) + #endif /* QEMU_SYSEMU_KVM_XEN_H */ diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c index c210ff9d91..75bcf7b630 100644 --- a/target/i386/kvm/xen-emu.c +++ b/target/i386/kvm/xen-emu.c @@ -23,6 +23,7 @@ #include "hw/pci/msi.h" #include "hw/i386/apic-msidef.h" +#include "hw/i386/e820_memory_layout.h" #include "hw/i386/kvm/xen_overlay.h" #include "hw/i386/kvm/xen_evtchn.h" #include "hw/i386/kvm/xen_gnttab.h" @@ -169,6 +170,15 @@ int kvm_xen_init(KVMState *s, uint32_t hypercall_msr) } s->xen_caps = xen_caps; + + /* Tell fw_cfg to notify the BIOS to reserve the range. */ + ret = e820_add_entry(XEN_SPECIAL_AREA_ADDR, XEN_SPECIAL_AREA_SIZE, + E820_RESERVED); + if (ret < 0) { + fprintf(stderr, "e820_add_entry() table is full\n"); + return ret; + } + return 0; } -- 2.11.0