[v6,00/14] KVM/X86: Introduce a new guest mapping interface
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KarimAllah Ahmed Jan. 31, 2019, 8:24 p.m. UTC
Guest memory can either be directly managed by the kernel (i.e. have a "struct
page") or they can simply live outside kernel control (i.e. do not have a
"struct page"). KVM mostly support these two modes, except in a few places
where the code seems to assume that guest memory must have a "struct page".

This patchset introduces a new mapping interface to map guest memory into host
kernel memory which also supports PFN-based memory (i.e. memory without 'struct
page'). It also converts all offending code to this interface or simply
read/write directly from guest memory. Patch 2 is additionally fixing an
incorrect page release and marking the page as dirty (i.e. as a side-effect of
using the helper function to write).

As far as I can see all offending code is now fixed except the APIC-access page
which I will handle in a seperate series along with dropping
kvm_vcpu_gfn_to_page and kvm_vcpu_gpa_to_page from the internal KVM API.

The current implementation of the new API uses memremap to map memory that does
not have a "struct page". This proves to be very slow for high frequency
mappings. Since this does not affect the normal use-case where a "struct page"
is available, the performance of this API will be handled by a seperate patch
series.

So the simple way to use memory outside kernel control is:

1- Pass 'mem=' in the kernel command-line to limit the amount of memory managed 
   by the kernel.
2- Map this physical memory you want to give to the guest with:
   mmap("/dev/mem", physical_address_offset, ..)
3- Use the user-space virtual address as the "userspace_addr" field in
   KVM_SET_USER_MEMORY_REGION ioctl.

v5 -> v6:
- Added one extra patch to ensure that support for this mem= case is complete
  for x86.
- Added a helper function to check if the mapping is mapped or not.
- Added more comments on the struct.
- Setting ->page to NULL on unmap and to a poison ptr if unused during map
- Checking for map ptr before using it.
- Change kvm_vcpu_unmap to also mark page dirty for LM. That requires
  passing the vCPU pointer again to this function.

v4 -> v5:
- Introduce a new parameter 'dirty' into kvm_vcpu_unmap
- A horrible rebase due to nested.c :)
- Dropped a couple of hyperv patches as the code was fixed already as a
  side-effect of another patch.
- Added a new trivial cleanup patch.

v3 -> v4:
- Rebase
- Add a new patch to also fix the newly introduced enlightned VMCS.

v2 -> v3:
- Rebase
- Add a new patch to also fix the newly introduced shadow VMCS.

Filippo Sironi (1):
  X86/KVM: Handle PFNs outside of kernel reach when touching GPTEs

KarimAllah Ahmed (13):
  X86/nVMX: handle_vmon: Read 4 bytes from guest memory
  X86/nVMX: Update the PML table without mapping and unmapping the page
  KVM: Introduce a new guest mapping API
  X86/nVMX: handle_vmptrld: Use kvm_vcpu_map when copying VMCS12 from
    guest memory
  KVM/nVMX: Use kvm_vcpu_map when mapping the L1 MSR bitmap
  KVM/nVMX: Use kvm_vcpu_map when mapping the virtual APIC page
  KVM/nVMX: Use kvm_vcpu_map when mapping the posted interrupt
    descriptor table
  KVM/X86: Use kvm_vcpu_map in emulator_cmpxchg_emulated
  KVM/nSVM: Use the new mapping API for mapping guest memory
  KVM/nVMX: Use kvm_vcpu_map for accessing the shadow VMCS
  KVM/nVMX: Use kvm_vcpu_map for accessing the enlightened VMCS
  KVM/nVMX: Use page_address_valid in a few more locations
  kvm, x86: Properly check whether a pfn is an MMIO or not

 arch/x86/include/asm/e820/api.h |   1 +
 arch/x86/kernel/e820.c          |  18 ++++-
 arch/x86/kvm/mmu.c              |   5 +-
 arch/x86/kvm/paging_tmpl.h      |  38 +++++++---
 arch/x86/kvm/svm.c              |  97 ++++++++++++------------
 arch/x86/kvm/vmx/nested.c       | 160 +++++++++++++++-------------------------
 arch/x86/kvm/vmx/vmx.c          |  19 ++---
 arch/x86/kvm/vmx/vmx.h          |   9 ++-
 arch/x86/kvm/x86.c              |  14 ++--
 include/linux/kvm_host.h        |  28 +++++++
 virt/kvm/kvm_main.c             |  64 ++++++++++++++++
 11 files changed, 267 insertions(+), 186 deletions(-)

Comments

KarimAllah Ahmed March 18, 2019, 1:10 p.m. UTC | #1
I guess this patch series missed the 5.1 merge window? :)

On Thu, 2019-01-31 at 21:24 +0100, KarimAllah Ahmed wrote:
> Guest memory can either be directly managed by the kernel (i.e. have a "struct
> page") or they can simply live outside kernel control (i.e. do not have a
> "struct page"). KVM mostly support these two modes, except in a few places
> where the code seems to assume that guest memory must have a "struct page".
> 
> This patchset introduces a new mapping interface to map guest memory into host
> kernel memory which also supports PFN-based memory (i.e. memory without 'struct
> page'). It also converts all offending code to this interface or simply
> read/write directly from guest memory. Patch 2 is additionally fixing an
> incorrect page release and marking the page as dirty (i.e. as a side-effect of
> using the helper function to write).
> 
> As far as I can see all offending code is now fixed except the APIC-access page
> which I will handle in a seperate series along with dropping
> kvm_vcpu_gfn_to_page and kvm_vcpu_gpa_to_page from the internal KVM API.
> 
> The current implementation of the new API uses memremap to map memory that does
> not have a "struct page". This proves to be very slow for high frequency
> mappings. Since this does not affect the normal use-case where a "struct page"
> is available, the performance of this API will be handled by a seperate patch
> series.
> 
> So the simple way to use memory outside kernel control is:
> 
> 1- Pass 'mem=' in the kernel command-line to limit the amount of memory managed 
>    by the kernel.
> 2- Map this physical memory you want to give to the guest with:
>    mmap("/dev/mem", physical_address_offset, ..)
> 3- Use the user-space virtual address as the "userspace_addr" field in
>    KVM_SET_USER_MEMORY_REGION ioctl.
> 
> v5 -> v6:
> - Added one extra patch to ensure that support for this mem= case is complete
>   for x86.
> - Added a helper function to check if the mapping is mapped or not.
> - Added more comments on the struct.
> - Setting ->page to NULL on unmap and to a poison ptr if unused during map
> - Checking for map ptr before using it.
> - Change kvm_vcpu_unmap to also mark page dirty for LM. That requires
>   passing the vCPU pointer again to this function.
> 
> v4 -> v5:
> - Introduce a new parameter 'dirty' into kvm_vcpu_unmap
> - A horrible rebase due to nested.c :)
> - Dropped a couple of hyperv patches as the code was fixed already as a
>   side-effect of another patch.
> - Added a new trivial cleanup patch.
> 
> v3 -> v4:
> - Rebase
> - Add a new patch to also fix the newly introduced enlightned VMCS.
> 
> v2 -> v3:
> - Rebase
> - Add a new patch to also fix the newly introduced shadow VMCS.
> 
> Filippo Sironi (1):
>   X86/KVM: Handle PFNs outside of kernel reach when touching GPTEs
> 
> KarimAllah Ahmed (13):
>   X86/nVMX: handle_vmon: Read 4 bytes from guest memory
>   X86/nVMX: Update the PML table without mapping and unmapping the page
>   KVM: Introduce a new guest mapping API
>   X86/nVMX: handle_vmptrld: Use kvm_vcpu_map when copying VMCS12 from
>     guest memory
>   KVM/nVMX: Use kvm_vcpu_map when mapping the L1 MSR bitmap
>   KVM/nVMX: Use kvm_vcpu_map when mapping the virtual APIC page
>   KVM/nVMX: Use kvm_vcpu_map when mapping the posted interrupt
>     descriptor table
>   KVM/X86: Use kvm_vcpu_map in emulator_cmpxchg_emulated
>   KVM/nSVM: Use the new mapping API for mapping guest memory
>   KVM/nVMX: Use kvm_vcpu_map for accessing the shadow VMCS
>   KVM/nVMX: Use kvm_vcpu_map for accessing the enlightened VMCS
>   KVM/nVMX: Use page_address_valid in a few more locations
>   kvm, x86: Properly check whether a pfn is an MMIO or not
> 
>  arch/x86/include/asm/e820/api.h |   1 +
>  arch/x86/kernel/e820.c          |  18 ++++-
>  arch/x86/kvm/mmu.c              |   5 +-
>  arch/x86/kvm/paging_tmpl.h      |  38 +++++++---
>  arch/x86/kvm/svm.c              |  97 ++++++++++++------------
>  arch/x86/kvm/vmx/nested.c       | 160 +++++++++++++++-------------------------
>  arch/x86/kvm/vmx/vmx.c          |  19 ++---
>  arch/x86/kvm/vmx/vmx.h          |   9 ++-
>  arch/x86/kvm/x86.c              |  14 ++--
>  include/linux/kvm_host.h        |  28 +++++++
>  virt/kvm/kvm_main.c             |  64 ++++++++++++++++
>  11 files changed, 267 insertions(+), 186 deletions(-)
> 



Amazon Development Center Germany GmbH
Krausenstr. 38
10117 Berlin
Geschaeftsfuehrer: Christian Schlaeger, Ralf Herbrich
Ust-ID: DE 289 237 879
Eingetragen am Amtsgericht Charlottenburg HRB 149173 B
Konrad Rzeszutek Wilk March 18, 2019, 2:22 p.m. UTC | #2
On Mon, Mar 18, 2019 at 01:10:24PM +0000, Raslan, KarimAllah wrote:
> I guess this patch series missed the 5.1 merge window? :)

Were there any outstanding fixes that had to be addressed?

> 
> On Thu, 2019-01-31 at 21:24 +0100, KarimAllah Ahmed wrote:
> > Guest memory can either be directly managed by the kernel (i.e. have a "struct
> > page") or they can simply live outside kernel control (i.e. do not have a
> > "struct page"). KVM mostly support these two modes, except in a few places
> > where the code seems to assume that guest memory must have a "struct page".
> > 
> > This patchset introduces a new mapping interface to map guest memory into host
> > kernel memory which also supports PFN-based memory (i.e. memory without 'struct
> > page'). It also converts all offending code to this interface or simply
> > read/write directly from guest memory. Patch 2 is additionally fixing an
> > incorrect page release and marking the page as dirty (i.e. as a side-effect of
> > using the helper function to write).
> > 
> > As far as I can see all offending code is now fixed except the APIC-access page
> > which I will handle in a seperate series along with dropping
> > kvm_vcpu_gfn_to_page and kvm_vcpu_gpa_to_page from the internal KVM API.
> > 
> > The current implementation of the new API uses memremap to map memory that does
> > not have a "struct page". This proves to be very slow for high frequency
> > mappings. Since this does not affect the normal use-case where a "struct page"
> > is available, the performance of this API will be handled by a seperate patch
> > series.
> > 
> > So the simple way to use memory outside kernel control is:
> > 
> > 1- Pass 'mem=' in the kernel command-line to limit the amount of memory managed 
> >    by the kernel.
> > 2- Map this physical memory you want to give to the guest with:
> >    mmap("/dev/mem", physical_address_offset, ..)
> > 3- Use the user-space virtual address as the "userspace_addr" field in
> >    KVM_SET_USER_MEMORY_REGION ioctl.
> > 
> > v5 -> v6:
> > - Added one extra patch to ensure that support for this mem= case is complete
> >   for x86.
> > - Added a helper function to check if the mapping is mapped or not.
> > - Added more comments on the struct.
> > - Setting ->page to NULL on unmap and to a poison ptr if unused during map
> > - Checking for map ptr before using it.
> > - Change kvm_vcpu_unmap to also mark page dirty for LM. That requires
> >   passing the vCPU pointer again to this function.
> > 
> > v4 -> v5:
> > - Introduce a new parameter 'dirty' into kvm_vcpu_unmap
> > - A horrible rebase due to nested.c :)
> > - Dropped a couple of hyperv patches as the code was fixed already as a
> >   side-effect of another patch.
> > - Added a new trivial cleanup patch.
> > 
> > v3 -> v4:
> > - Rebase
> > - Add a new patch to also fix the newly introduced enlightned VMCS.
> > 
> > v2 -> v3:
> > - Rebase
> > - Add a new patch to also fix the newly introduced shadow VMCS.
> > 
> > Filippo Sironi (1):
> >   X86/KVM: Handle PFNs outside of kernel reach when touching GPTEs
> > 
> > KarimAllah Ahmed (13):
> >   X86/nVMX: handle_vmon: Read 4 bytes from guest memory
> >   X86/nVMX: Update the PML table without mapping and unmapping the page
> >   KVM: Introduce a new guest mapping API
> >   X86/nVMX: handle_vmptrld: Use kvm_vcpu_map when copying VMCS12 from
> >     guest memory
> >   KVM/nVMX: Use kvm_vcpu_map when mapping the L1 MSR bitmap
> >   KVM/nVMX: Use kvm_vcpu_map when mapping the virtual APIC page
> >   KVM/nVMX: Use kvm_vcpu_map when mapping the posted interrupt
> >     descriptor table
> >   KVM/X86: Use kvm_vcpu_map in emulator_cmpxchg_emulated
> >   KVM/nSVM: Use the new mapping API for mapping guest memory
> >   KVM/nVMX: Use kvm_vcpu_map for accessing the shadow VMCS
> >   KVM/nVMX: Use kvm_vcpu_map for accessing the enlightened VMCS
> >   KVM/nVMX: Use page_address_valid in a few more locations
> >   kvm, x86: Properly check whether a pfn is an MMIO or not
> > 
> >  arch/x86/include/asm/e820/api.h |   1 +
> >  arch/x86/kernel/e820.c          |  18 ++++-
> >  arch/x86/kvm/mmu.c              |   5 +-
> >  arch/x86/kvm/paging_tmpl.h      |  38 +++++++---
> >  arch/x86/kvm/svm.c              |  97 ++++++++++++------------
> >  arch/x86/kvm/vmx/nested.c       | 160 +++++++++++++++-------------------------
> >  arch/x86/kvm/vmx/vmx.c          |  19 ++---
> >  arch/x86/kvm/vmx/vmx.h          |   9 ++-
> >  arch/x86/kvm/x86.c              |  14 ++--
> >  include/linux/kvm_host.h        |  28 +++++++
> >  virt/kvm/kvm_main.c             |  64 ++++++++++++++++
> >  11 files changed, 267 insertions(+), 186 deletions(-)
> > 
> 
> 
> 
> Amazon Development Center Germany GmbH
> Krausenstr. 38
> 10117 Berlin
> Geschaeftsfuehrer: Christian Schlaeger, Ralf Herbrich
> Ust-ID: DE 289 237 879
> Eingetragen am Amtsgericht Charlottenburg HRB 149173 B
>
KarimAllah Ahmed March 18, 2019, 7:16 p.m. UTC | #3
On Mon, 2019-03-18 at 10:22 -0400, Konrad Rzeszutek Wilk wrote:
> On Mon, Mar 18, 2019 at 01:10:24PM +0000, Raslan, KarimAllah wrote:
> > 
> > I guess this patch series missed the 5.1 merge window? :)
> 
> Were there any outstanding fixes that had to be addressed?

Not as far as I can remember. This version addressed all requests raised in 
'v5'.

> 
> > 
> > 
> > On Thu, 2019-01-31 at 21:24 +0100, KarimAllah Ahmed wrote:
> > > 
> > > Guest memory can either be directly managed by the kernel (i.e. have a "struct
> > > page") or they can simply live outside kernel control (i.e. do not have a
> > > "struct page"). KVM mostly support these two modes, except in a few places
> > > where the code seems to assume that guest memory must have a "struct page".
> > > 
> > > This patchset introduces a new mapping interface to map guest memory into host
> > > kernel memory which also supports PFN-based memory (i.e. memory without 'struct
> > > page'). It also converts all offending code to this interface or simply
> > > read/write directly from guest memory. Patch 2 is additionally fixing an
> > > incorrect page release and marking the page as dirty (i.e. as a side-effect of
> > > using the helper function to write).
> > > 
> > > As far as I can see all offending code is now fixed except the APIC-access page
> > > which I will handle in a seperate series along with dropping
> > > kvm_vcpu_gfn_to_page and kvm_vcpu_gpa_to_page from the internal KVM API.
> > > 
> > > The current implementation of the new API uses memremap to map memory that does
> > > not have a "struct page". This proves to be very slow for high frequency
> > > mappings. Since this does not affect the normal use-case where a "struct page"
> > > is available, the performance of this API will be handled by a seperate patch
> > > series.
> > > 
> > > So the simple way to use memory outside kernel control is:
> > > 
> > > 1- Pass 'mem=' in the kernel command-line to limit the amount of memory managed 
> > >    by the kernel.
> > > 2- Map this physical memory you want to give to the guest with:
> > >    mmap("/dev/mem", physical_address_offset, ..)
> > > 3- Use the user-space virtual address as the "userspace_addr" field in
> > >    KVM_SET_USER_MEMORY_REGION ioctl.
> > > 
> > > v5 -> v6:
> > > - Added one extra patch to ensure that support for this mem= case is complete
> > >   for x86.
> > > - Added a helper function to check if the mapping is mapped or not.
> > > - Added more comments on the struct.
> > > - Setting ->page to NULL on unmap and to a poison ptr if unused during map
> > > - Checking for map ptr before using it.
> > > - Change kvm_vcpu_unmap to also mark page dirty for LM. That requires
> > >   passing the vCPU pointer again to this function.
> > > 
> > > v4 -> v5:
> > > - Introduce a new parameter 'dirty' into kvm_vcpu_unmap
> > > - A horrible rebase due to nested.c :)
> > > - Dropped a couple of hyperv patches as the code was fixed already as a
> > >   side-effect of another patch.
> > > - Added a new trivial cleanup patch.
> > > 
> > > v3 -> v4:
> > > - Rebase
> > > - Add a new patch to also fix the newly introduced enlightned VMCS.
> > > 
> > > v2 -> v3:
> > > - Rebase
> > > - Add a new patch to also fix the newly introduced shadow VMCS.
> > > 
> > > Filippo Sironi (1):
> > >   X86/KVM: Handle PFNs outside of kernel reach when touching GPTEs
> > > 
> > > KarimAllah Ahmed (13):
> > >   X86/nVMX: handle_vmon: Read 4 bytes from guest memory
> > >   X86/nVMX: Update the PML table without mapping and unmapping the page
> > >   KVM: Introduce a new guest mapping API
> > >   X86/nVMX: handle_vmptrld: Use kvm_vcpu_map when copying VMCS12 from
> > >     guest memory
> > >   KVM/nVMX: Use kvm_vcpu_map when mapping the L1 MSR bitmap
> > >   KVM/nVMX: Use kvm_vcpu_map when mapping the virtual APIC page
> > >   KVM/nVMX: Use kvm_vcpu_map when mapping the posted interrupt
> > >     descriptor table
> > >   KVM/X86: Use kvm_vcpu_map in emulator_cmpxchg_emulated
> > >   KVM/nSVM: Use the new mapping API for mapping guest memory
> > >   KVM/nVMX: Use kvm_vcpu_map for accessing the shadow VMCS
> > >   KVM/nVMX: Use kvm_vcpu_map for accessing the enlightened VMCS
> > >   KVM/nVMX: Use page_address_valid in a few more locations
> > >   kvm, x86: Properly check whether a pfn is an MMIO or not
> > > 
> > >  arch/x86/include/asm/e820/api.h |   1 +
> > >  arch/x86/kernel/e820.c          |  18 ++++-
> > >  arch/x86/kvm/mmu.c              |   5 +-
> > >  arch/x86/kvm/paging_tmpl.h      |  38 +++++++---
> > >  arch/x86/kvm/svm.c              |  97 ++++++++++++------------
> > >  arch/x86/kvm/vmx/nested.c       | 160 +++++++++++++++-------------------------
> > >  arch/x86/kvm/vmx/vmx.c          |  19 ++---
> > >  arch/x86/kvm/vmx/vmx.h          |   9 ++-
> > >  arch/x86/kvm/x86.c              |  14 ++--
> > >  include/linux/kvm_host.h        |  28 +++++++
> > >  virt/kvm/kvm_main.c             |  64 ++++++++++++++++
> > >  11 files changed, 267 insertions(+), 186 deletions(-)
> > > 
> > 
> > 
> > 
> > Amazon Development Center Germany GmbH
> > Krausenstr. 38
> > 10117 Berlin
> > Geschaeftsfuehrer: Christian Schlaeger, Ralf Herbrich
> > Ust-ID: DE 289 237 879
> > Eingetragen am Amtsgericht Charlottenburg HRB 149173 B
> > 



Amazon Development Center Germany GmbH
Krausenstr. 38
10117 Berlin
Geschaeftsfuehrer: Christian Schlaeger, Ralf Herbrich
Ust-ID: DE 289 237 879
Eingetragen am Amtsgericht Charlottenburg HRB 149173 B
Konrad Rzeszutek Wilk April 29, 2019, 1:58 p.m. UTC | #4
On Mon, Mar 18, 2019 at 07:16:28PM +0000, Raslan, KarimAllah wrote:
> On Mon, 2019-03-18 at 10:22 -0400, Konrad Rzeszutek Wilk wrote:
> > On Mon, Mar 18, 2019 at 01:10:24PM +0000, Raslan, KarimAllah wrote:
> > > 
> > > I guess this patch series missed the 5.1 merge window? :)
> > 
> > Were there any outstanding fixes that had to be addressed?
> 
> Not as far as I can remember. This version addressed all requests raised in 
> 'v5'.

Paolo,

Are there any concerns in pulling this patchset in?

Thank you!
> 
> > 
> > > 
> > > 
> > > On Thu, 2019-01-31 at 21:24 +0100, KarimAllah Ahmed wrote:
> > > > 
> > > > Guest memory can either be directly managed by the kernel (i.e. have a "struct
> > > > page") or they can simply live outside kernel control (i.e. do not have a
> > > > "struct page"). KVM mostly support these two modes, except in a few places
> > > > where the code seems to assume that guest memory must have a "struct page".
> > > > 
> > > > This patchset introduces a new mapping interface to map guest memory into host
> > > > kernel memory which also supports PFN-based memory (i.e. memory without 'struct
> > > > page'). It also converts all offending code to this interface or simply
> > > > read/write directly from guest memory. Patch 2 is additionally fixing an
> > > > incorrect page release and marking the page as dirty (i.e. as a side-effect of
> > > > using the helper function to write).
> > > > 
> > > > As far as I can see all offending code is now fixed except the APIC-access page
> > > > which I will handle in a seperate series along with dropping
> > > > kvm_vcpu_gfn_to_page and kvm_vcpu_gpa_to_page from the internal KVM API.
> > > > 
> > > > The current implementation of the new API uses memremap to map memory that does
> > > > not have a "struct page". This proves to be very slow for high frequency
> > > > mappings. Since this does not affect the normal use-case where a "struct page"
> > > > is available, the performance of this API will be handled by a seperate patch
> > > > series.
> > > > 
> > > > So the simple way to use memory outside kernel control is:
> > > > 
> > > > 1- Pass 'mem=' in the kernel command-line to limit the amount of memory managed 
> > > >    by the kernel.
> > > > 2- Map this physical memory you want to give to the guest with:
> > > >    mmap("/dev/mem", physical_address_offset, ..)
> > > > 3- Use the user-space virtual address as the "userspace_addr" field in
> > > >    KVM_SET_USER_MEMORY_REGION ioctl.
> > > > 
> > > > v5 -> v6:
> > > > - Added one extra patch to ensure that support for this mem= case is complete
> > > >   for x86.
> > > > - Added a helper function to check if the mapping is mapped or not.
> > > > - Added more comments on the struct.
> > > > - Setting ->page to NULL on unmap and to a poison ptr if unused during map
> > > > - Checking for map ptr before using it.
> > > > - Change kvm_vcpu_unmap to also mark page dirty for LM. That requires
> > > >   passing the vCPU pointer again to this function.
> > > > 
> > > > v4 -> v5:
> > > > - Introduce a new parameter 'dirty' into kvm_vcpu_unmap
> > > > - A horrible rebase due to nested.c :)
> > > > - Dropped a couple of hyperv patches as the code was fixed already as a
> > > >   side-effect of another patch.
> > > > - Added a new trivial cleanup patch.
> > > > 
> > > > v3 -> v4:
> > > > - Rebase
> > > > - Add a new patch to also fix the newly introduced enlightned VMCS.
> > > > 
> > > > v2 -> v3:
> > > > - Rebase
> > > > - Add a new patch to also fix the newly introduced shadow VMCS.
> > > > 
> > > > Filippo Sironi (1):
> > > >   X86/KVM: Handle PFNs outside of kernel reach when touching GPTEs
> > > > 
> > > > KarimAllah Ahmed (13):
> > > >   X86/nVMX: handle_vmon: Read 4 bytes from guest memory
> > > >   X86/nVMX: Update the PML table without mapping and unmapping the page
> > > >   KVM: Introduce a new guest mapping API
> > > >   X86/nVMX: handle_vmptrld: Use kvm_vcpu_map when copying VMCS12 from
> > > >     guest memory
> > > >   KVM/nVMX: Use kvm_vcpu_map when mapping the L1 MSR bitmap
> > > >   KVM/nVMX: Use kvm_vcpu_map when mapping the virtual APIC page
> > > >   KVM/nVMX: Use kvm_vcpu_map when mapping the posted interrupt
> > > >     descriptor table
> > > >   KVM/X86: Use kvm_vcpu_map in emulator_cmpxchg_emulated
> > > >   KVM/nSVM: Use the new mapping API for mapping guest memory
> > > >   KVM/nVMX: Use kvm_vcpu_map for accessing the shadow VMCS
> > > >   KVM/nVMX: Use kvm_vcpu_map for accessing the enlightened VMCS
> > > >   KVM/nVMX: Use page_address_valid in a few more locations
> > > >   kvm, x86: Properly check whether a pfn is an MMIO or not
> > > > 
> > > >  arch/x86/include/asm/e820/api.h |   1 +
> > > >  arch/x86/kernel/e820.c          |  18 ++++-
> > > >  arch/x86/kvm/mmu.c              |   5 +-
> > > >  arch/x86/kvm/paging_tmpl.h      |  38 +++++++---
> > > >  arch/x86/kvm/svm.c              |  97 ++++++++++++------------
> > > >  arch/x86/kvm/vmx/nested.c       | 160 +++++++++++++++-------------------------
> > > >  arch/x86/kvm/vmx/vmx.c          |  19 ++---
> > > >  arch/x86/kvm/vmx/vmx.h          |   9 ++-
> > > >  arch/x86/kvm/x86.c              |  14 ++--
> > > >  include/linux/kvm_host.h        |  28 +++++++
> > > >  virt/kvm/kvm_main.c             |  64 ++++++++++++++++
> > > >  11 files changed, 267 insertions(+), 186 deletions(-)
> > > > 
> > > 
> > > 
> > > 
> > > Amazon Development Center Germany GmbH
> > > Krausenstr. 38
> > > 10117 Berlin
> > > Geschaeftsfuehrer: Christian Schlaeger, Ralf Herbrich
> > > Ust-ID: DE 289 237 879
> > > Eingetragen am Amtsgericht Charlottenburg HRB 149173 B
> > > 
> 
> 
> 
> Amazon Development Center Germany GmbH
> Krausenstr. 38
> 10117 Berlin
> Geschaeftsfuehrer: Christian Schlaeger, Ralf Herbrich
> Ust-ID: DE 289 237 879
> Eingetragen am Amtsgericht Charlottenburg HRB 149173 B
>
Paolo Bonzini April 30, 2019, 7:31 p.m. UTC | #5
On 29/04/19 15:58, Konrad Rzeszutek Wilk wrote:
> On Mon, Mar 18, 2019 at 07:16:28PM +0000, Raslan, KarimAllah wrote:
>> On Mon, 2019-03-18 at 10:22 -0400, Konrad Rzeszutek Wilk wrote:
>>> On Mon, Mar 18, 2019 at 01:10:24PM +0000, Raslan, KarimAllah wrote:
>>>>
>>>> I guess this patch series missed the 5.1 merge window? :)
>>>
>>> Were there any outstanding fixes that had to be addressed?
>>
>> Not as far as I can remember. This version addressed all requests raised in 
>> 'v5'.
> 
> Paolo,
> 
> Are there any concerns in pulling this patchset in?

No, it should be in 5.2.

Paolo

> 
> Thank you!
>>
>>>
>>>>
>>>>
>>>> On Thu, 2019-01-31 at 21:24 +0100, KarimAllah Ahmed wrote:
>>>>>
>>>>> Guest memory can either be directly managed by the kernel (i.e. have a "struct
>>>>> page") or they can simply live outside kernel control (i.e. do not have a
>>>>> "struct page"). KVM mostly support these two modes, except in a few places
>>>>> where the code seems to assume that guest memory must have a "struct page".
>>>>>
>>>>> This patchset introduces a new mapping interface to map guest memory into host
>>>>> kernel memory which also supports PFN-based memory (i.e. memory without 'struct
>>>>> page'). It also converts all offending code to this interface or simply
>>>>> read/write directly from guest memory. Patch 2 is additionally fixing an
>>>>> incorrect page release and marking the page as dirty (i.e. as a side-effect of
>>>>> using the helper function to write).
>>>>>
>>>>> As far as I can see all offending code is now fixed except the APIC-access page
>>>>> which I will handle in a seperate series along with dropping
>>>>> kvm_vcpu_gfn_to_page and kvm_vcpu_gpa_to_page from the internal KVM API.
>>>>>
>>>>> The current implementation of the new API uses memremap to map memory that does
>>>>> not have a "struct page". This proves to be very slow for high frequency
>>>>> mappings. Since this does not affect the normal use-case where a "struct page"
>>>>> is available, the performance of this API will be handled by a seperate patch
>>>>> series.
>>>>>
>>>>> So the simple way to use memory outside kernel control is:
>>>>>
>>>>> 1- Pass 'mem=' in the kernel command-line to limit the amount of memory managed 
>>>>>    by the kernel.
>>>>> 2- Map this physical memory you want to give to the guest with:
>>>>>    mmap("/dev/mem", physical_address_offset, ..)
>>>>> 3- Use the user-space virtual address as the "userspace_addr" field in
>>>>>    KVM_SET_USER_MEMORY_REGION ioctl.
>>>>>
>>>>> v5 -> v6:
>>>>> - Added one extra patch to ensure that support for this mem= case is complete
>>>>>   for x86.
>>>>> - Added a helper function to check if the mapping is mapped or not.
>>>>> - Added more comments on the struct.
>>>>> - Setting ->page to NULL on unmap and to a poison ptr if unused during map
>>>>> - Checking for map ptr before using it.
>>>>> - Change kvm_vcpu_unmap to also mark page dirty for LM. That requires
>>>>>   passing the vCPU pointer again to this function.
>>>>>
>>>>> v4 -> v5:
>>>>> - Introduce a new parameter 'dirty' into kvm_vcpu_unmap
>>>>> - A horrible rebase due to nested.c :)
>>>>> - Dropped a couple of hyperv patches as the code was fixed already as a
>>>>>   side-effect of another patch.
>>>>> - Added a new trivial cleanup patch.
>>>>>
>>>>> v3 -> v4:
>>>>> - Rebase
>>>>> - Add a new patch to also fix the newly introduced enlightned VMCS.
>>>>>
>>>>> v2 -> v3:
>>>>> - Rebase
>>>>> - Add a new patch to also fix the newly introduced shadow VMCS.
>>>>>
>>>>> Filippo Sironi (1):
>>>>>   X86/KVM: Handle PFNs outside of kernel reach when touching GPTEs
>>>>>
>>>>> KarimAllah Ahmed (13):
>>>>>   X86/nVMX: handle_vmon: Read 4 bytes from guest memory
>>>>>   X86/nVMX: Update the PML table without mapping and unmapping the page
>>>>>   KVM: Introduce a new guest mapping API
>>>>>   X86/nVMX: handle_vmptrld: Use kvm_vcpu_map when copying VMCS12 from
>>>>>     guest memory
>>>>>   KVM/nVMX: Use kvm_vcpu_map when mapping the L1 MSR bitmap
>>>>>   KVM/nVMX: Use kvm_vcpu_map when mapping the virtual APIC page
>>>>>   KVM/nVMX: Use kvm_vcpu_map when mapping the posted interrupt
>>>>>     descriptor table
>>>>>   KVM/X86: Use kvm_vcpu_map in emulator_cmpxchg_emulated
>>>>>   KVM/nSVM: Use the new mapping API for mapping guest memory
>>>>>   KVM/nVMX: Use kvm_vcpu_map for accessing the shadow VMCS
>>>>>   KVM/nVMX: Use kvm_vcpu_map for accessing the enlightened VMCS
>>>>>   KVM/nVMX: Use page_address_valid in a few more locations
>>>>>   kvm, x86: Properly check whether a pfn is an MMIO or not
>>>>>
>>>>>  arch/x86/include/asm/e820/api.h |   1 +
>>>>>  arch/x86/kernel/e820.c          |  18 ++++-
>>>>>  arch/x86/kvm/mmu.c              |   5 +-
>>>>>  arch/x86/kvm/paging_tmpl.h      |  38 +++++++---
>>>>>  arch/x86/kvm/svm.c              |  97 ++++++++++++------------
>>>>>  arch/x86/kvm/vmx/nested.c       | 160 +++++++++++++++-------------------------
>>>>>  arch/x86/kvm/vmx/vmx.c          |  19 ++---
>>>>>  arch/x86/kvm/vmx/vmx.h          |   9 ++-
>>>>>  arch/x86/kvm/x86.c              |  14 ++--
>>>>>  include/linux/kvm_host.h        |  28 +++++++
>>>>>  virt/kvm/kvm_main.c             |  64 ++++++++++++++++
>>>>>  11 files changed, 267 insertions(+), 186 deletions(-)
>>>>>
>>>>
>>>>
>>>>
>>>> Amazon Development Center Germany GmbH
>>>> Krausenstr. 38
>>>> 10117 Berlin
>>>> Geschaeftsfuehrer: Christian Schlaeger, Ralf Herbrich
>>>> Ust-ID: DE 289 237 879
>>>> Eingetragen am Amtsgericht Charlottenburg HRB 149173 B
>>>>
>>
>>
>>
>> Amazon Development Center Germany GmbH
>> Krausenstr. 38
>> 10117 Berlin
>> Geschaeftsfuehrer: Christian Schlaeger, Ralf Herbrich
>> Ust-ID: DE 289 237 879
>> Eingetragen am Amtsgericht Charlottenburg HRB 149173 B
>>