Hi Henry,
On 11/05/2024 01:56, Henry Wang wrote:
Currently the GUEST_MAGIC_BASE in the init-dom0less application is
hardcoded, which will lead to failures for 1:1 direct-mapped Dom0less
DomUs.
Since the guest magic region is now allocated from the hypervisor,
instead of hardcoding the guest magic pages region, use
xc_hvm_param_get() to get the guest magic region PFN, and based on
that the XenStore PFN can be calculated. Also, we don't need to set
the max mem anymore, so drop the call to xc_domain_setmaxmem(). Rename
the alloc_xs_page() to get_xs_page() to reflect the changes.
Take the opportunity to do some coding style improvements when possible.
Reported-by: Alec Kwapis <alec.kwa...@medtronic.com>
Signed-off-by: Henry Wang <xin.wa...@amd.com>
---
v2:
- Update HVMOP keys name.
---
tools/helpers/init-dom0less.c | 40 +++++++++++++++--------------------
1 file changed, 17 insertions(+), 23 deletions(-)
diff --git a/tools/helpers/init-dom0less.c b/tools/helpers/init-dom0less.c
index fee93459c4..04039a2a66 100644
--- a/tools/helpers/init-dom0less.c
+++ b/tools/helpers/init-dom0less.c
@@ -19,24 +19,20 @@
#define XENSTORE_PFN_OFFSET 1
Based on previous discussion, I think this wants to be 0 so the
hypervisor only need to allocate one page (rather than 2 with the
current offset).
#define STR_MAX_LENGTH 128
-static int alloc_xs_page(struct xc_interface_core *xch,
- libxl_dominfo *info,
- uint64_t *xenstore_pfn)
+static int get_xs_page(struct xc_interface_core *xch, libxl_dominfo *info,
+ uint64_t *xenstore_pfn)
{
int rc;
- const xen_pfn_t base = GUEST_MAGIC_BASE >> XC_PAGE_SHIFT;
- xen_pfn_t p2m = (GUEST_MAGIC_BASE >> XC_PAGE_SHIFT) + XENSTORE_PFN_OFFSET;
+ xen_pfn_t magic_base_pfn;
- rc = xc_domain_setmaxmem(xch, info->domid,
- info->max_memkb + (XC_PAGE_SIZE/1024));
- if (rc < 0)
- return rc;
-
- rc = xc_domain_populate_physmap_exact(xch, info->domid, 1, 0, 0, &p2m);
- if (rc < 0)
- return rc;
+ rc = xc_hvm_param_get(xch, info->domid, HVM_PARAM_HV_RSRV_BASE_PFN,
+ &magic_base_pfn);
+ if (rc < 0) {
+ printf("Failed to get HVM_PARAM_HV_RSRV_BASE_PFN\n");
+ return 1;
+ }
If we go down the route of using HVM_PARAM... then we should avoid to
rely on the hypervisor to provide a large enough region. So we should
check the offset against the size.
Cheers,
--
Julien Grall
