diff mbox series

[v5,3/9] x86/sgx: Keep record for SGX VA and Guest page type

Message ID 20220520103904.1216-4-cathy.zhang@intel.com (mailing list archive)
State New, archived
Headers show
Series Support microcode updates affecting SGX | expand

Commit Message

Zhang, Cathy May 20, 2022, 10:38 a.m. UTC
Regular enclave EPC pages have sgx_encl_page as their owner, but
SGX VA page and KVM guest EPC page are maintained by different
owner structures.

SGX CPUSVN update requires to know the EPC page owner's status
and then decide how to handle the page.

Keep a record of page type for SGX VA and KVM guest page while
the other EPC pages already have their type tracked, so that
CPUSVN update can get EPC page's owner by type and handle it then.

Signed-off-by: Cathy Zhang <cathy.zhang@intel.com>

---
Changes since v3:
 - Rename SGX_EPC_PAGE_GUEST as SGX_EPC_PAGE_KVM_GUEST. (Suggested by
   Jarkko, Sakkinen)
---
 arch/x86/kernel/cpu/sgx/sgx.h  | 4 ++++
 arch/x86/kernel/cpu/sgx/encl.c | 2 ++
 arch/x86/kernel/cpu/sgx/virt.c | 2 ++
 3 files changed, 8 insertions(+)

Comments

Jarkko Sakkinen May 20, 2022, 7:11 p.m. UTC | #1
On Fri, May 20, 2022 at 06:38:58PM +0800, Cathy Zhang wrote:
> Regular enclave EPC pages have sgx_encl_page as their owner, but
> SGX VA page and KVM guest EPC page are maintained by different
> owner structures.
> 
> SGX CPUSVN update requires to know the EPC page owner's status
> and then decide how to handle the page.
> 
> Keep a record of page type for SGX VA and KVM guest page while
> the other EPC pages already have their type tracked, so that
> CPUSVN update can get EPC page's owner by type and handle it then.
> 
> Signed-off-by: Cathy Zhang <cathy.zhang@intel.com>
> 
> ---
> Changes since v3:
>  - Rename SGX_EPC_PAGE_GUEST as SGX_EPC_PAGE_KVM_GUEST. (Suggested by
>    Jarkko, Sakkinen)
> ---
>  arch/x86/kernel/cpu/sgx/sgx.h  | 4 ++++
>  arch/x86/kernel/cpu/sgx/encl.c | 2 ++
>  arch/x86/kernel/cpu/sgx/virt.c | 2 ++
>  3 files changed, 8 insertions(+)
> 
> diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h
> index f8ed9deac18b..4ad0e5396eef 100644
> --- a/arch/x86/kernel/cpu/sgx/sgx.h
> +++ b/arch/x86/kernel/cpu/sgx/sgx.h
> @@ -28,6 +28,10 @@
>  
>  /* Pages on free list */
>  #define SGX_EPC_PAGE_IS_FREE		BIT(1)
> +/* VA page */
> +#define SGX_EPC_PAGE_VA			BIT(2)
> +/* Pages allocated for KVM guest */
> +#define SGX_EPC_PAGE_KVM_GUEST		BIT(3)
>  
>  struct sgx_epc_page {
>  	unsigned int section;
> diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
> index 08f39fa03a39..383abd538ac9 100644
> --- a/arch/x86/kernel/cpu/sgx/encl.c
> +++ b/arch/x86/kernel/cpu/sgx/encl.c
> @@ -912,6 +912,8 @@ struct sgx_epc_page *sgx_alloc_va_page(struct sgx_va_page *va_page)
>  		return ERR_PTR(-EFAULT);
>  	}
>  
> +	epc_page->flags |= SGX_EPC_PAGE_VA;
> +
>  	return epc_page;
>  }
>  
> diff --git a/arch/x86/kernel/cpu/sgx/virt.c b/arch/x86/kernel/cpu/sgx/virt.c
> index e953816d7c8b..104487b72fb8 100644
> --- a/arch/x86/kernel/cpu/sgx/virt.c
> +++ b/arch/x86/kernel/cpu/sgx/virt.c
> @@ -50,6 +50,8 @@ static int __sgx_vepc_fault(struct sgx_vepc *vepc,
>  	if (IS_ERR(epc_page))
>  		return PTR_ERR(epc_page);
>  
> +	epc_page->flags |= SGX_EPC_PAGE_KVM_GUEST;

This would need to be synced up with SGX_EPC_IS_VEPC:

https://lore.kernel.org/linux-sgx/694234d7-6a0d-e85f-f2f9-e52b4a61e1ec@intel.com/T/#t

Otherwise, we have a chaos.

Can you sync up with Zhiquan Li and find some common approach. IMHO,
it might even sense to merge these patch sets into one. Then it would
be easier to review them as a whole.

BR, Jarkko
Zhang, Cathy May 23, 2022, 12:06 a.m. UTC | #2
Hi Jarkko,

> -----Original Message-----
> From: Jarkko Sakkinen <jarkko@kernel.org>
> Sent: Saturday, May 21, 2022 3:11 AM
> To: Zhang, Cathy <cathy.zhang@intel.com>; Li, Zhiquan1
> <zhiquan1.li@intel.com>
> Cc: linux-sgx@vger.kernel.org; x86@kernel.org; Chatre, Reinette
> <reinette.chatre@intel.com>; Hansen, Dave <dave.hansen@intel.com>; Raj,
> Ashok <ashok.raj@intel.com>; chao.p.peng@linux.intel.com; Zhong, Yang
> <yang.zhong@intel.com>
> Subject: Re: [PATCH v5 3/9] x86/sgx: Keep record for SGX VA and Guest page
> type
> 
> On Fri, May 20, 2022 at 06:38:58PM +0800, Cathy Zhang wrote:
> > Regular enclave EPC pages have sgx_encl_page as their owner, but SGX
> > VA page and KVM guest EPC page are maintained by different owner
> > structures.
> >
> > SGX CPUSVN update requires to know the EPC page owner's status and
> > then decide how to handle the page.
> >
> > Keep a record of page type for SGX VA and KVM guest page while the
> > other EPC pages already have their type tracked, so that CPUSVN update
> > can get EPC page's owner by type and handle it then.
> >
> > Signed-off-by: Cathy Zhang <cathy.zhang@intel.com>
> >
> > ---
> > Changes since v3:
> >  - Rename SGX_EPC_PAGE_GUEST as SGX_EPC_PAGE_KVM_GUEST.
> (Suggested by
> >    Jarkko, Sakkinen)
> > ---
> >  arch/x86/kernel/cpu/sgx/sgx.h  | 4 ++++
> > arch/x86/kernel/cpu/sgx/encl.c | 2 ++  arch/x86/kernel/cpu/sgx/virt.c
> > | 2 ++
> >  3 files changed, 8 insertions(+)
> >
> > diff --git a/arch/x86/kernel/cpu/sgx/sgx.h
> > b/arch/x86/kernel/cpu/sgx/sgx.h index f8ed9deac18b..4ad0e5396eef
> > 100644
> > --- a/arch/x86/kernel/cpu/sgx/sgx.h
> > +++ b/arch/x86/kernel/cpu/sgx/sgx.h
> > @@ -28,6 +28,10 @@
> >
> >  /* Pages on free list */
> >  #define SGX_EPC_PAGE_IS_FREE		BIT(1)
> > +/* VA page */
> > +#define SGX_EPC_PAGE_VA			BIT(2)
> > +/* Pages allocated for KVM guest */
> > +#define SGX_EPC_PAGE_KVM_GUEST		BIT(3)
> >
> >  struct sgx_epc_page {
> >  	unsigned int section;
> > diff --git a/arch/x86/kernel/cpu/sgx/encl.c
> > b/arch/x86/kernel/cpu/sgx/encl.c index 08f39fa03a39..383abd538ac9
> > 100644
> > --- a/arch/x86/kernel/cpu/sgx/encl.c
> > +++ b/arch/x86/kernel/cpu/sgx/encl.c
> > @@ -912,6 +912,8 @@ struct sgx_epc_page *sgx_alloc_va_page(struct
> sgx_va_page *va_page)
> >  		return ERR_PTR(-EFAULT);
> >  	}
> >
> > +	epc_page->flags |= SGX_EPC_PAGE_VA;
> > +
> >  	return epc_page;
> >  }
> >
> > diff --git a/arch/x86/kernel/cpu/sgx/virt.c
> > b/arch/x86/kernel/cpu/sgx/virt.c index e953816d7c8b..104487b72fb8
> > 100644
> > --- a/arch/x86/kernel/cpu/sgx/virt.c
> > +++ b/arch/x86/kernel/cpu/sgx/virt.c
> > @@ -50,6 +50,8 @@ static int __sgx_vepc_fault(struct sgx_vepc *vepc,
> >  	if (IS_ERR(epc_page))
> >  		return PTR_ERR(epc_page);
> >
> > +	epc_page->flags |= SGX_EPC_PAGE_KVM_GUEST;
> 
> This would need to be synced up with SGX_EPC_IS_VEPC:
> 
> https://lore.kernel.org/linux-sgx/694234d7-6a0d-e85f-f2f9-
> e52b4a61e1ec@intel.com/T/#t
> 
> Otherwise, we have a chaos.
> 
> Can you sync up with Zhiquan Li and find some common approach. IMHO, it
> might even sense to merge these patch sets into one. Then it would be easier
> to review them as a whole.

Thanks for showing the above related patches, Jarkko! I just take a quick look at that series,
AFAIK, __sgx_vepc_fault() will only be called during VM boot up to allocate physical EPC pages.
Then, host does not know how VM works with those pages. VM SGX driver will handle any errors itself.
So with the approach in that series, what it actually tracks is the vaddr in QEMU address space
for all EPC pages allocated to the VM. Does host need to track such information? QEMU side
should provide it easily I think. @Li, Zhiquan1.

> 
> BR, Jarkko
Zhang, Cathy May 23, 2022, 6:09 a.m. UTC | #3
Hi Jarkko,

> -----Original Message-----
> From: Zhang, Cathy
> Sent: Monday, May 23, 2022 8:07 AM
> To: 'Jarkko Sakkinen' <jarkko@kernel.org>; Li, Zhiquan1
> <zhiquan1.li@intel.com>
> Cc: linux-sgx@vger.kernel.org; x86@kernel.org; Chatre, Reinette
> <reinette.chatre@intel.com>; Hansen, Dave <dave.hansen@intel.com>; Raj,
> Ashok <ashok.raj@intel.com>; chao.p.peng@linux.intel.com; Zhong, Yang
> <yang.zhong@intel.com>
> Subject: RE: [PATCH v5 3/9] x86/sgx: Keep record for SGX VA and Guest page
> type
> 
> Hi Jarkko,
> 
> > -----Original Message-----
> > From: Jarkko Sakkinen <jarkko@kernel.org>
> > Sent: Saturday, May 21, 2022 3:11 AM
> > To: Zhang, Cathy <cathy.zhang@intel.com>; Li, Zhiquan1
> > <zhiquan1.li@intel.com>
> > Cc: linux-sgx@vger.kernel.org; x86@kernel.org; Chatre, Reinette
> > <reinette.chatre@intel.com>; Hansen, Dave <dave.hansen@intel.com>;
> > Raj, Ashok <ashok.raj@intel.com>; chao.p.peng@linux.intel.com; Zhong,
> > Yang <yang.zhong@intel.com>
> > Subject: Re: [PATCH v5 3/9] x86/sgx: Keep record for SGX VA and Guest
> > page type
> >
> > On Fri, May 20, 2022 at 06:38:58PM +0800, Cathy Zhang wrote:
> > > Regular enclave EPC pages have sgx_encl_page as their owner, but SGX
> > > VA page and KVM guest EPC page are maintained by different owner
> > > structures.
> > >
> > > SGX CPUSVN update requires to know the EPC page owner's status and
> > > then decide how to handle the page.
> > >
> > > Keep a record of page type for SGX VA and KVM guest page while the
> > > other EPC pages already have their type tracked, so that CPUSVN
> > > update can get EPC page's owner by type and handle it then.
> > >
> > > Signed-off-by: Cathy Zhang <cathy.zhang@intel.com>
> > >
> > > ---
> > > Changes since v3:
> > >  - Rename SGX_EPC_PAGE_GUEST as SGX_EPC_PAGE_KVM_GUEST.
> > (Suggested by
> > >    Jarkko, Sakkinen)
> > > ---
> > >  arch/x86/kernel/cpu/sgx/sgx.h  | 4 ++++
> > > arch/x86/kernel/cpu/sgx/encl.c | 2 ++
> > > arch/x86/kernel/cpu/sgx/virt.c
> > > | 2 ++
> > >  3 files changed, 8 insertions(+)
> > >
> > > diff --git a/arch/x86/kernel/cpu/sgx/sgx.h
> > > b/arch/x86/kernel/cpu/sgx/sgx.h index f8ed9deac18b..4ad0e5396eef
> > > 100644
> > > --- a/arch/x86/kernel/cpu/sgx/sgx.h
> > > +++ b/arch/x86/kernel/cpu/sgx/sgx.h
> > > @@ -28,6 +28,10 @@
> > >
> > >  /* Pages on free list */
> > >  #define SGX_EPC_PAGE_IS_FREE		BIT(1)
> > > +/* VA page */
> > > +#define SGX_EPC_PAGE_VA			BIT(2)
> > > +/* Pages allocated for KVM guest */
> > > +#define SGX_EPC_PAGE_KVM_GUEST		BIT(3)
> > >
> > >  struct sgx_epc_page {
> > >  	unsigned int section;
> > > diff --git a/arch/x86/kernel/cpu/sgx/encl.c
> > > b/arch/x86/kernel/cpu/sgx/encl.c index 08f39fa03a39..383abd538ac9
> > > 100644
> > > --- a/arch/x86/kernel/cpu/sgx/encl.c
> > > +++ b/arch/x86/kernel/cpu/sgx/encl.c
> > > @@ -912,6 +912,8 @@ struct sgx_epc_page *sgx_alloc_va_page(struct
> > sgx_va_page *va_page)
> > >  		return ERR_PTR(-EFAULT);
> > >  	}
> > >
> > > +	epc_page->flags |= SGX_EPC_PAGE_VA;
> > > +
> > >  	return epc_page;
> > >  }
> > >
> > > diff --git a/arch/x86/kernel/cpu/sgx/virt.c
> > > b/arch/x86/kernel/cpu/sgx/virt.c index e953816d7c8b..104487b72fb8
> > > 100644
> > > --- a/arch/x86/kernel/cpu/sgx/virt.c
> > > +++ b/arch/x86/kernel/cpu/sgx/virt.c
> > > @@ -50,6 +50,8 @@ static int __sgx_vepc_fault(struct sgx_vepc *vepc,
> > >  	if (IS_ERR(epc_page))
> > >  		return PTR_ERR(epc_page);
> > >
> > > +	epc_page->flags |= SGX_EPC_PAGE_KVM_GUEST;
> >
> > This would need to be synced up with SGX_EPC_IS_VEPC:
> >
> > https://lore.kernel.org/linux-sgx/694234d7-6a0d-e85f-f2f9-
> > e52b4a61e1ec@intel.com/T/#t
> >
> > Otherwise, we have a chaos.
> >
> > Can you sync up with Zhiquan Li and find some common approach. IMHO,
> > it might even sense to merge these patch sets into one. Then it would
> > be easier to review them as a whole.
> 
> Thanks for showing the above related patches, Jarkko! I just take a quick look
> at that series, AFAIK, __sgx_vepc_fault() will only be called during VM boot
> up to allocate physical EPC pages.
> Then, host does not know how VM works with those pages. VM SGX driver
> will handle any errors itself.
> So with the approach in that series, what it actually tracks is the vaddr in
> QEMU address space for all EPC pages allocated to the VM. Does host need
> to track such information? QEMU side should provide it easily I think. @Li,
> Zhiquan1.
> 

I've synced with Zhiquan Li and got the whole picture of his patch logic. I suggest
to follow the way how we handle the same change between EDMM and Seamless,
that is Zhiquan Li will apply patch 3 from Seamless and then add his left patches.
Please let's know if you have other suggestion. Thanks!

> >
> > BR, Jarkko
Jarkko Sakkinen May 23, 2022, 7:19 p.m. UTC | #4
On Mon, May 23, 2022 at 06:09:55AM +0000, Zhang, Cathy wrote:
> Hi Jarkko,
> 
> > -----Original Message-----
> > From: Zhang, Cathy
> > Sent: Monday, May 23, 2022 8:07 AM
> > To: 'Jarkko Sakkinen' <jarkko@kernel.org>; Li, Zhiquan1
> > <zhiquan1.li@intel.com>
> > Cc: linux-sgx@vger.kernel.org; x86@kernel.org; Chatre, Reinette
> > <reinette.chatre@intel.com>; Hansen, Dave <dave.hansen@intel.com>; Raj,
> > Ashok <ashok.raj@intel.com>; chao.p.peng@linux.intel.com; Zhong, Yang
> > <yang.zhong@intel.com>
> > Subject: RE: [PATCH v5 3/9] x86/sgx: Keep record for SGX VA and Guest page
> > type
> > 
> > Hi Jarkko,
> > 
> > > -----Original Message-----
> > > From: Jarkko Sakkinen <jarkko@kernel.org>
> > > Sent: Saturday, May 21, 2022 3:11 AM
> > > To: Zhang, Cathy <cathy.zhang@intel.com>; Li, Zhiquan1
> > > <zhiquan1.li@intel.com>
> > > Cc: linux-sgx@vger.kernel.org; x86@kernel.org; Chatre, Reinette
> > > <reinette.chatre@intel.com>; Hansen, Dave <dave.hansen@intel.com>;
> > > Raj, Ashok <ashok.raj@intel.com>; chao.p.peng@linux.intel.com; Zhong,
> > > Yang <yang.zhong@intel.com>
> > > Subject: Re: [PATCH v5 3/9] x86/sgx: Keep record for SGX VA and Guest
> > > page type
> > >
> > > On Fri, May 20, 2022 at 06:38:58PM +0800, Cathy Zhang wrote:
> > > > Regular enclave EPC pages have sgx_encl_page as their owner, but SGX
> > > > VA page and KVM guest EPC page are maintained by different owner
> > > > structures.
> > > >
> > > > SGX CPUSVN update requires to know the EPC page owner's status and
> > > > then decide how to handle the page.
> > > >
> > > > Keep a record of page type for SGX VA and KVM guest page while the
> > > > other EPC pages already have their type tracked, so that CPUSVN
> > > > update can get EPC page's owner by type and handle it then.
> > > >
> > > > Signed-off-by: Cathy Zhang <cathy.zhang@intel.com>
> > > >
> > > > ---
> > > > Changes since v3:
> > > >  - Rename SGX_EPC_PAGE_GUEST as SGX_EPC_PAGE_KVM_GUEST.
> > > (Suggested by
> > > >    Jarkko, Sakkinen)
> > > > ---
> > > >  arch/x86/kernel/cpu/sgx/sgx.h  | 4 ++++
> > > > arch/x86/kernel/cpu/sgx/encl.c | 2 ++
> > > > arch/x86/kernel/cpu/sgx/virt.c
> > > > | 2 ++
> > > >  3 files changed, 8 insertions(+)
> > > >
> > > > diff --git a/arch/x86/kernel/cpu/sgx/sgx.h
> > > > b/arch/x86/kernel/cpu/sgx/sgx.h index f8ed9deac18b..4ad0e5396eef
> > > > 100644
> > > > --- a/arch/x86/kernel/cpu/sgx/sgx.h
> > > > +++ b/arch/x86/kernel/cpu/sgx/sgx.h
> > > > @@ -28,6 +28,10 @@
> > > >
> > > >  /* Pages on free list */
> > > >  #define SGX_EPC_PAGE_IS_FREE		BIT(1)
> > > > +/* VA page */
> > > > +#define SGX_EPC_PAGE_VA			BIT(2)
> > > > +/* Pages allocated for KVM guest */
> > > > +#define SGX_EPC_PAGE_KVM_GUEST		BIT(3)
> > > >
> > > >  struct sgx_epc_page {
> > > >  	unsigned int section;
> > > > diff --git a/arch/x86/kernel/cpu/sgx/encl.c
> > > > b/arch/x86/kernel/cpu/sgx/encl.c index 08f39fa03a39..383abd538ac9
> > > > 100644
> > > > --- a/arch/x86/kernel/cpu/sgx/encl.c
> > > > +++ b/arch/x86/kernel/cpu/sgx/encl.c
> > > > @@ -912,6 +912,8 @@ struct sgx_epc_page *sgx_alloc_va_page(struct
> > > sgx_va_page *va_page)
> > > >  		return ERR_PTR(-EFAULT);
> > > >  	}
> > > >
> > > > +	epc_page->flags |= SGX_EPC_PAGE_VA;
> > > > +
> > > >  	return epc_page;
> > > >  }
> > > >
> > > > diff --git a/arch/x86/kernel/cpu/sgx/virt.c
> > > > b/arch/x86/kernel/cpu/sgx/virt.c index e953816d7c8b..104487b72fb8
> > > > 100644
> > > > --- a/arch/x86/kernel/cpu/sgx/virt.c
> > > > +++ b/arch/x86/kernel/cpu/sgx/virt.c
> > > > @@ -50,6 +50,8 @@ static int __sgx_vepc_fault(struct sgx_vepc *vepc,
> > > >  	if (IS_ERR(epc_page))
> > > >  		return PTR_ERR(epc_page);
> > > >
> > > > +	epc_page->flags |= SGX_EPC_PAGE_KVM_GUEST;
> > >
> > > This would need to be synced up with SGX_EPC_IS_VEPC:
> > >
> > > https://lore.kernel.org/linux-sgx/694234d7-6a0d-e85f-f2f9-
> > > e52b4a61e1ec@intel.com/T/#t
> > >
> > > Otherwise, we have a chaos.
> > >
> > > Can you sync up with Zhiquan Li and find some common approach. IMHO,
> > > it might even sense to merge these patch sets into one. Then it would
> > > be easier to review them as a whole.
> > 
> > Thanks for showing the above related patches, Jarkko! I just take a quick look
> > at that series, AFAIK, __sgx_vepc_fault() will only be called during VM boot
> > up to allocate physical EPC pages.
> > Then, host does not know how VM works with those pages. VM SGX driver
> > will handle any errors itself.
> > So with the approach in that series, what it actually tracks is the vaddr in
> > QEMU address space for all EPC pages allocated to the VM. Does host need
> > to track such information? QEMU side should provide it easily I think. @Li,
> > Zhiquan1.
> > 
> 
> I've synced with Zhiquan Li and got the whole picture of his patch logic. I suggest
> to follow the way how we handle the same change between EDMM and Seamless,
> that is Zhiquan Li will apply patch 3 from Seamless and then add his left patches.
> Please let's know if you have other suggestion. Thanks!

Sounds reasonable!

BR, Jarkko
diff mbox series

Patch

diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h
index f8ed9deac18b..4ad0e5396eef 100644
--- a/arch/x86/kernel/cpu/sgx/sgx.h
+++ b/arch/x86/kernel/cpu/sgx/sgx.h
@@ -28,6 +28,10 @@ 
 
 /* Pages on free list */
 #define SGX_EPC_PAGE_IS_FREE		BIT(1)
+/* VA page */
+#define SGX_EPC_PAGE_VA			BIT(2)
+/* Pages allocated for KVM guest */
+#define SGX_EPC_PAGE_KVM_GUEST		BIT(3)
 
 struct sgx_epc_page {
 	unsigned int section;
diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
index 08f39fa03a39..383abd538ac9 100644
--- a/arch/x86/kernel/cpu/sgx/encl.c
+++ b/arch/x86/kernel/cpu/sgx/encl.c
@@ -912,6 +912,8 @@  struct sgx_epc_page *sgx_alloc_va_page(struct sgx_va_page *va_page)
 		return ERR_PTR(-EFAULT);
 	}
 
+	epc_page->flags |= SGX_EPC_PAGE_VA;
+
 	return epc_page;
 }
 
diff --git a/arch/x86/kernel/cpu/sgx/virt.c b/arch/x86/kernel/cpu/sgx/virt.c
index e953816d7c8b..104487b72fb8 100644
--- a/arch/x86/kernel/cpu/sgx/virt.c
+++ b/arch/x86/kernel/cpu/sgx/virt.c
@@ -50,6 +50,8 @@  static int __sgx_vepc_fault(struct sgx_vepc *vepc,
 	if (IS_ERR(epc_page))
 		return PTR_ERR(epc_page);
 
+	epc_page->flags |= SGX_EPC_PAGE_KVM_GUEST;
+
 	ret = xa_err(xa_store(&vepc->page_array, index, epc_page, GFP_KERNEL));
 	if (ret)
 		goto err_free;