From: Joao Martins <joao.m.mart...@oracle.com>
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 <joao.m.mart...@oracle.com>
[dwmw2: Use the xen_overlay device]
Signed-off-by: David Woodhouse <d...@amazon.co.uk>
---
target/i386/trace-events | 1 +
target/i386/xen.c | 59 +++++++++++++++++++++++++++++++++++++++-
2 files changed, 59 insertions(+), 1 deletion(-)
diff --git a/target/i386/trace-events b/target/i386/trace-events
index 1bf9558811..fb999d0052 100644
--- a/target/i386/trace-events
+++ b/target/i386/trace-events
@@ -14,3 +14,4 @@ kvm_sev_attestation_report(const char *mnonce, const char
*data) "mnonce %s data
# target/i386/xen.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_set_shared_info(uint64_t gfn) "shared info at gfn 0x%" PRIx64
diff --git a/target/i386/xen.c b/target/i386/xen.c
index 55beed1913..ddd144039a 100644
--- a/target/i386/xen.c
+++ b/target/i386/xen.c
@@ -15,8 +15,9 @@
#include "exec/address-spaces.h"
#include "xen.h"
#include "trace.h"
-
+#include "hw/i386/kvm/xen_overlay.h"
#include "standard-headers/xen/version.h"
+#include "standard-headers/xen/memory.h"
static int kvm_gva_rw(CPUState *cs, uint64_t gva, void *_buf, size_t sz,
bool is_write)
@@ -126,6 +127,59 @@ static bool kvm_xen_hcall_xen_version(struct kvm_xen_exit
*exit, X86CPU *cpu,
return true;
}
+static int xen_set_shared_info(CPUState *cs, uint64_t gfn)
+{
+ uint64_t gpa = gfn << TARGET_PAGE_BITS;
+ int err;
+
+ /* 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_page(XENMAPSPACE_shared_info, 0, gpa);
+ if (err)
+ return err;
+
+ trace_kvm_xen_set_shared_info(gfn);
+
+ return err;
+}
+
+static bool kvm_xen_hcall_memory_op(struct kvm_xen_exit *exit,
+ int cmd, uint64_t arg, X86CPU *cpu)
+{
+ CPUState *cs = CPU(cpu);
+ int err = 0;
+
+ switch (cmd) {
+ case XENMEM_add_to_physmap: {
+ struct xen_add_to_physmap xatp;
+
+ err = kvm_copy_from_gva(cs, arg, &xatp, sizeof(xatp));
+ if (err) {
+ break;
+ }
+
+ switch (xatp.space) {
+ case XENMAPSPACE_shared_info:
+ break;
+ default:
+ err = -ENOSYS;
+ break;
+ }
+
+ err = xen_set_shared_info(cs, xatp.gpfn);
+ break;
+ }
+
+ default:
+ return false;
+ }
+
+ exit->u.hcall.result = err;
+ return true;
+}
+
static bool __kvm_xen_handle_exit(X86CPU *cpu, struct kvm_xen_exit *exit)
{
uint16_t code = exit->u.hcall.input;
@@ -136,6 +190,9 @@ static bool __kvm_xen_handle_exit(X86CPU *cpu, struct
kvm_xen_exit *exit)
}
switch (code) {
+ case __HYPERVISOR_memory_op:
+ return kvm_xen_hcall_memory_op(exit, exit->u.hcall.params[0],
+ exit->u.hcall.params[1], cpu);
case __HYPERVISOR_xen_version:
return kvm_xen_hcall_xen_version(exit, cpu, exit->u.hcall.params[0],
exit->u.hcall.params[1]);
--
2.35.3
