[xen stable-4.15] x86/mem_sharing: copy parent VM's hostp2m's max_mapped_pfn during forking

[patchbot@xxxxxxx]

commit b712639084b91917a24304dc3d6b019c386b279a
Author:     Tamas K Lengyel <tamas.lengyel@xxxxxxxxx>
AuthorDate: Fri Mar 26 16:23:00 2021 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Fri Mar 26 16:23:00 2021 +0100

    x86/mem_sharing: copy parent VM's hostp2m's max_mapped_pfn during forking
    
    When creating a VM fork copy the parent VM's hostp2m max_mapped_pfn value. 
Some
    toolstack relies on the XENMEM_maximum_gpfn value to establish the maximum
    addressable physical memory in the VM and for forks that have not yet been
    unpaused that value is not going to reflect the correct max gpfn that's
    possible to populate into the p2m. This patch fixes the issue.
    
    Signed-off-by: Tamas K Lengyel <tamas.lengyel@xxxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Release-Acked-by: Ian Jackson <iwj@xxxxxxxxxxxxxx>
    master commit: f10c41537113dc2406c26cdf134403864df02a7d
    master date: 2021-03-26 16:17:07 +0100
---
 xen/arch/x86/mm/mem_sharing.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/xen/arch/x86/mm/mem_sharing.c b/xen/arch/x86/mm/mem_sharing.c
index 00ada05c10..98b14f7b0a 100644
--- a/xen/arch/x86/mm/mem_sharing.c
+++ b/xen/arch/x86/mm/mem_sharing.c
@@ -1761,6 +1761,7 @@ static int copy_settings(struct domain *cd, struct domain 
*d)
         return rc;
 
     copy_tsc(cd, d);
+    p2m_get_hostp2m(cd)->max_mapped_pfn = p2m_get_hostp2m(d)->max_mapped_pfn;
 
     return rc;
 }
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.15