Re: [RHEL-8.1 virt 2/2] target/i386: sev: Do not pin the ram device memory region

[Gary R Hook]

----- Original Message -----
> From: "Gary R Hook" <address@hidden>
> To: address@hidden
> Cc: address@hidden, "Paolo Bonzini" <address@hidden>, address@hidden, 
> "Eduardo Habkost"
> <address@hidden>, "Richard Henderson" <address@hidden>
> Sent: Tuesday, April 9, 2019 7:08:03 PM
> Subject: [RHEL-8.1 virt 2/2] target/i386: sev: Do not pin the ram device      
> memory region
> 
> BZ: 1667249
> Branch: rhel-8.1.0
> Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1667249
> Upstream Status: 4.0.0-rc1
> Build Info:
> https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=20980582
> Conflicts: None
> 
> commit cedc0ad539afbbb669dba9e73dfad2915bc1c25b
> Author: Singh, Brijesh <address@hidden>
> Date:   Mon Feb 4 22:23:40 2019 +0000
> 
>     target/i386: sev: Do not pin the ram device memory region
> 
>     The RAM device presents a memory region that should be handled
>     as an IO region and should not be pinned.
> 
>     In the case of the vfio-pci, RAM device represents a MMIO BAR
>     and the memory region is not backed by pages hence
>     KVM_MEMORY_ENCRYPT_REG_REGION fails to lock the memory range.
> 
>     Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1667249
>     Cc: Alex Williamson <address@hidden>
>     Cc: Paolo Bonzini <address@hidden>
>     Signed-off-by: Brijesh Singh <address@hidden>
>     Message-Id: <address@hidden>
>     Signed-off-by: Paolo Bonzini <address@hidden>
> 
> Cc: Paolo Bonzini <address@hidden>
> Cc: Richard Henderson <address@hidden>
> Cc: Eduardo Habkost <address@hidden>
> Cc: address@hidden

NACKed-by: Gary R Hook <address@hidden>

> ---
>  target/i386/sev.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/target/i386/sev.c b/target/i386/sev.c
> index 2395171acf..b8009b001a 100644
> --- a/target/i386/sev.c
> +++ b/target/i386/sev.c
> @@ -130,6 +130,17 @@ sev_ram_block_added(RAMBlockNotifier *n, void *host,
> size_t size)
>  {
>      int r;
>      struct kvm_enc_region range;
> +    ram_addr_t offset;
> +    MemoryRegion *mr;
> +
> +    /*
> +     * The RAM device presents a memory region that should be treated
> +     * as IO region and should not be pinned.
> +     */
> +    mr = memory_region_from_host(host, &offset);
> +    if (mr && memory_region_is_ram_device(mr)) {
> +     return;
> +    }
>  
>      range.addr = (__u64)(unsigned long)host;
>      range.size = size;
> --
> 2.18.1
> 
>