| Message ID | 20190117215300.29694-3-brijesh.singh@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Fix SEV VM device assignment | expand |
On Thu, 17 Jan 2019 21:53:16 +0000 "Singh, Brijesh" <brijesh.singh@amd.com> wrote: > 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 <alex.williamson@redhat.com> > Cc: Paolo Bonzini <pbonzini@redhat.com> > Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> > --- > target/i386/sev.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/target/i386/sev.c b/target/i386/sev.c > index 20b2d325d8..3e9d5c02fa 100644 > --- a/target/i386/sev.c > +++ b/target/i386/sev.c > @@ -131,6 +131,17 @@ sev_ram_block_added(RAMBlockNotifier *n, void *host, size_t size) > { > int r; > struct kvm_enc_region range; > + ram_addr_t offset; > + MemoryRegion *mr; > + > + mr = memory_region_from_host(host, &offset); > + /* > + * The RAM device presents a memory region that should be treated > + * as IO region and should not be pinned. > + */ > + if (memory_region_is_ram_device(mr)) { > + return; > + } > > range.addr = (__u64)(unsigned long)host; > range.size = size; memory_region_from_host() can return NULL, which would give you a segfault at memory_region_is_ram_device(), so you might want to test mr on it's own first and decide which path that would take. Thanks, Alex
On 2/4/19 11:59 AM, Alex Williamson wrote: > On Thu, 17 Jan 2019 21:53:16 +0000 > "Singh, Brijesh" <brijesh.singh@amd.com> wrote: > >> 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 <alex.williamson@redhat.com> >> Cc: Paolo Bonzini <pbonzini@redhat.com> >> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> >> --- >> target/i386/sev.c | 11 +++++++++++ >> 1 file changed, 11 insertions(+) >> >> diff --git a/target/i386/sev.c b/target/i386/sev.c >> index 20b2d325d8..3e9d5c02fa 100644 >> --- a/target/i386/sev.c >> +++ b/target/i386/sev.c >> @@ -131,6 +131,17 @@ sev_ram_block_added(RAMBlockNotifier *n, void *host, size_t size) >> { >> int r; >> struct kvm_enc_region range; >> + ram_addr_t offset; >> + MemoryRegion *mr; >> + >> + mr = memory_region_from_host(host, &offset); >> + /* >> + * The RAM device presents a memory region that should be treated >> + * as IO region and should not be pinned. >> + */ >> + if (memory_region_is_ram_device(mr)) { >> + return; >> + } >> >> range.addr = (__u64)(unsigned long)host; >> range.size = size; > > > memory_region_from_host() can return NULL, which would give you a > segfault at memory_region_is_ram_device(), so you might want to test mr > on it's own first and decide which path that would take. Thanks, > Ah, thanks for catching it. I will fix in v2.
diff --git a/target/i386/sev.c b/target/i386/sev.c index 20b2d325d8..3e9d5c02fa 100644 --- a/target/i386/sev.c +++ b/target/i386/sev.c @@ -131,6 +131,17 @@ sev_ram_block_added(RAMBlockNotifier *n, void *host, size_t size) { int r; struct kvm_enc_region range; + ram_addr_t offset; + MemoryRegion *mr; + + mr = memory_region_from_host(host, &offset); + /* + * The RAM device presents a memory region that should be treated + * as IO region and should not be pinned. + */ + if (memory_region_is_ram_device(mr)) { + return; + } range.addr = (__u64)(unsigned long)host; range.size = size;
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 <alex.williamson@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> --- target/i386/sev.c | 11 +++++++++++ 1 file changed, 11 insertions(+)