diff mbox series

[v6,10/14] mm: x86: Invoke hypercall when page encryption status is changed

Message ID 05c9015fb13b25c07a84d5638a7cd65a8c136cf0.1585548051.git.ashish.kalra@amd.com (mailing list archive)
State New, archived
Headers show
Series Add AMD SEV guest live migration support | expand

Commit Message

Kalra, Ashish March 30, 2020, 6:22 a.m. UTC
From: Brijesh Singh <Brijesh.Singh@amd.com>

Invoke a hypercall when a memory region is changed from encrypted ->
decrypted and vice versa. Hypervisor need to know the page encryption
status during the guest migration.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
---
 arch/x86/include/asm/paravirt.h       | 10 +++++
 arch/x86/include/asm/paravirt_types.h |  2 +
 arch/x86/kernel/paravirt.c            |  1 +
 arch/x86/mm/mem_encrypt.c             | 57 ++++++++++++++++++++++++++-
 arch/x86/mm/pat/set_memory.c          |  7 ++++
 5 files changed, 76 insertions(+), 1 deletion(-)

Comments

Krish Sadhukhan April 3, 2020, 9:07 p.m. UTC | #1
On 3/29/20 11:22 PM, Ashish Kalra wrote:
> From: Brijesh Singh <Brijesh.Singh@amd.com>
>
> Invoke a hypercall when a memory region is changed from encrypted ->
> decrypted and vice versa. Hypervisor need to know the page encryption
> status during the guest migration.
>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: "Radim Krčmář" <rkrcmar@redhat.com>
> Cc: Joerg Roedel <joro@8bytes.org>
> Cc: Borislav Petkov <bp@suse.de>
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Cc: x86@kernel.org
> Cc: kvm@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
> ---
>   arch/x86/include/asm/paravirt.h       | 10 +++++
>   arch/x86/include/asm/paravirt_types.h |  2 +
>   arch/x86/kernel/paravirt.c            |  1 +
>   arch/x86/mm/mem_encrypt.c             | 57 ++++++++++++++++++++++++++-
>   arch/x86/mm/pat/set_memory.c          |  7 ++++
>   5 files changed, 76 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
> index 694d8daf4983..8127b9c141bf 100644
> --- a/arch/x86/include/asm/paravirt.h
> +++ b/arch/x86/include/asm/paravirt.h
> @@ -78,6 +78,12 @@ static inline void paravirt_arch_exit_mmap(struct mm_struct *mm)
>   	PVOP_VCALL1(mmu.exit_mmap, mm);
>   }
>   
> +static inline void page_encryption_changed(unsigned long vaddr, int npages,
> +						bool enc)
> +{
> +	PVOP_VCALL3(mmu.page_encryption_changed, vaddr, npages, enc);
> +}
> +
>   #ifdef CONFIG_PARAVIRT_XXL
>   static inline void load_sp0(unsigned long sp0)
>   {
> @@ -946,6 +952,10 @@ static inline void paravirt_arch_dup_mmap(struct mm_struct *oldmm,
>   static inline void paravirt_arch_exit_mmap(struct mm_struct *mm)
>   {
>   }
> +
> +static inline void page_encryption_changed(unsigned long vaddr, int npages, bool enc)
> +{
> +}
>   #endif
>   #endif /* __ASSEMBLY__ */
>   #endif /* _ASM_X86_PARAVIRT_H */
> diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
> index 732f62e04ddb..03bfd515c59c 100644
> --- a/arch/x86/include/asm/paravirt_types.h
> +++ b/arch/x86/include/asm/paravirt_types.h
> @@ -215,6 +215,8 @@ struct pv_mmu_ops {
>   
>   	/* Hook for intercepting the destruction of an mm_struct. */
>   	void (*exit_mmap)(struct mm_struct *mm);
> +	void (*page_encryption_changed)(unsigned long vaddr, int npages,
> +					bool enc);
>   
>   #ifdef CONFIG_PARAVIRT_XXL
>   	struct paravirt_callee_save read_cr2;
> diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
> index c131ba4e70ef..840c02b23aeb 100644
> --- a/arch/x86/kernel/paravirt.c
> +++ b/arch/x86/kernel/paravirt.c
> @@ -367,6 +367,7 @@ struct paravirt_patch_template pv_ops = {
>   			(void (*)(struct mmu_gather *, void *))tlb_remove_page,
>   
>   	.mmu.exit_mmap		= paravirt_nop,
> +	.mmu.page_encryption_changed	= paravirt_nop,
>   
>   #ifdef CONFIG_PARAVIRT_XXL
>   	.mmu.read_cr2		= __PV_IS_CALLEE_SAVE(native_read_cr2),
> diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
> index f4bd4b431ba1..c9800fa811f6 100644
> --- a/arch/x86/mm/mem_encrypt.c
> +++ b/arch/x86/mm/mem_encrypt.c
> @@ -19,6 +19,7 @@
>   #include <linux/kernel.h>
>   #include <linux/bitops.h>
>   #include <linux/dma-mapping.h>
> +#include <linux/kvm_para.h>
>   
>   #include <asm/tlbflush.h>
>   #include <asm/fixmap.h>
> @@ -29,6 +30,7 @@
>   #include <asm/processor-flags.h>
>   #include <asm/msr.h>
>   #include <asm/cmdline.h>
> +#include <asm/kvm_para.h>
>   
>   #include "mm_internal.h"
>   
> @@ -196,6 +198,47 @@ void __init sme_early_init(void)
>   		swiotlb_force = SWIOTLB_FORCE;
>   }
>   
> +static void set_memory_enc_dec_hypercall(unsigned long vaddr, int npages,
> +					bool enc)
> +{
> +	unsigned long sz = npages << PAGE_SHIFT;
> +	unsigned long vaddr_end, vaddr_next;
> +
> +	vaddr_end = vaddr + sz;
> +
> +	for (; vaddr < vaddr_end; vaddr = vaddr_next) {
> +		int psize, pmask, level;
> +		unsigned long pfn;
> +		pte_t *kpte;
> +
> +		kpte = lookup_address(vaddr, &level);
> +		if (!kpte || pte_none(*kpte))
> +			return;
> +
> +		switch (level) {
> +		case PG_LEVEL_4K:
> +			pfn = pte_pfn(*kpte);
> +			break;
> +		case PG_LEVEL_2M:
> +			pfn = pmd_pfn(*(pmd_t *)kpte);
> +			break;
> +		case PG_LEVEL_1G:
> +			pfn = pud_pfn(*(pud_t *)kpte);
> +			break;
> +		default:
> +			return;
> +		}


Is it possible to re-use the code in __set_clr_pte_enc() ?

> +
> +		psize = page_level_size(level);
> +		pmask = page_level_mask(level);
> +
> +		kvm_sev_hypercall3(KVM_HC_PAGE_ENC_STATUS,
> +				   pfn << PAGE_SHIFT, psize >> PAGE_SHIFT, enc);
> +
> +		vaddr_next = (vaddr & pmask) + psize;
> +	}
> +}
> +
>   static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc)
>   {
>   	pgprot_t old_prot, new_prot;
> @@ -253,12 +296,13 @@ static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc)
>   static int __init early_set_memory_enc_dec(unsigned long vaddr,
>   					   unsigned long size, bool enc)
>   {
> -	unsigned long vaddr_end, vaddr_next;
> +	unsigned long vaddr_end, vaddr_next, start;
>   	unsigned long psize, pmask;
>   	int split_page_size_mask;
>   	int level, ret;
>   	pte_t *kpte;
>   
> +	start = vaddr;
>   	vaddr_next = vaddr;
>   	vaddr_end = vaddr + size;
>   
> @@ -313,6 +357,8 @@ static int __init early_set_memory_enc_dec(unsigned long vaddr,
>   
>   	ret = 0;
>   
> +	set_memory_enc_dec_hypercall(start, PAGE_ALIGN(size) >> PAGE_SHIFT,
> +					enc);


If I haven't missed anything, it seems early_set_memory_encrypted() 
doesn't have a caller. So is there a possibility that we can end up 
calling it in non-SEV context and hence do we need to have the 
sev_active() guard here ?

>   out:
>   	__flush_tlb_all();
>   	return ret;
> @@ -451,6 +497,15 @@ void __init mem_encrypt_init(void)
>   	if (sev_active())
>   		static_branch_enable(&sev_enable_key);
>   
> +#ifdef CONFIG_PARAVIRT
> +	/*
> +	 * With SEV, we need to make a hypercall when page encryption state is
> +	 * changed.
> +	 */
> +	if (sev_active())
> +		pv_ops.mmu.page_encryption_changed = set_memory_enc_dec_hypercall;
> +#endif
> +
>   	pr_info("AMD %s active\n",
>   		sev_active() ? "Secure Encrypted Virtualization (SEV)"
>   			     : "Secure Memory Encryption (SME)");
> diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
> index c4aedd00c1ba..86b7804129fc 100644
> --- a/arch/x86/mm/pat/set_memory.c
> +++ b/arch/x86/mm/pat/set_memory.c
> @@ -26,6 +26,7 @@
>   #include <asm/proto.h>
>   #include <asm/memtype.h>
>   #include <asm/set_memory.h>
> +#include <asm/paravirt.h>
>   
>   #include "../mm_internal.h"
>   
> @@ -1987,6 +1988,12 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
>   	 */
>   	cpa_flush(&cpa, 0);
>   
> +	/* Notify hypervisor that a given memory range is mapped encrypted
> +	 * or decrypted. The hypervisor will use this information during the
> +	 * VM migration.
> +	 */
> +	page_encryption_changed(addr, numpages, enc);
> +
>   	return ret;
>   }
>
Kalra, Ashish April 3, 2020, 9:30 p.m. UTC | #2
On Fri, Apr 03, 2020 at 02:07:02PM -0700, Krish Sadhukhan wrote:
> 
> On 3/29/20 11:22 PM, Ashish Kalra wrote:
> > From: Brijesh Singh <Brijesh.Singh@amd.com>
> > 
> > Invoke a hypercall when a memory region is changed from encrypted ->
> > decrypted and vice versa. Hypervisor need to know the page encryption
> > status during the guest migration.
> > 
> > Cc: Thomas Gleixner <tglx@linutronix.de>
> > Cc: Ingo Molnar <mingo@redhat.com>
> > Cc: "H. Peter Anvin" <hpa@zytor.com>
> > Cc: Paolo Bonzini <pbonzini@redhat.com>
> > Cc: "Radim Krčmář" <rkrcmar@redhat.com>
> > Cc: Joerg Roedel <joro@8bytes.org>
> > Cc: Borislav Petkov <bp@suse.de>
> > Cc: Tom Lendacky <thomas.lendacky@amd.com>
> > Cc: x86@kernel.org
> > Cc: kvm@vger.kernel.org
> > Cc: linux-kernel@vger.kernel.org
> > Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
> > Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
> > ---
> >   arch/x86/include/asm/paravirt.h       | 10 +++++
> >   arch/x86/include/asm/paravirt_types.h |  2 +
> >   arch/x86/kernel/paravirt.c            |  1 +
> >   arch/x86/mm/mem_encrypt.c             | 57 ++++++++++++++++++++++++++-
> >   arch/x86/mm/pat/set_memory.c          |  7 ++++
> >   5 files changed, 76 insertions(+), 1 deletion(-)
> > 
> > diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
> > index 694d8daf4983..8127b9c141bf 100644
> > --- a/arch/x86/include/asm/paravirt.h
> > +++ b/arch/x86/include/asm/paravirt.h
> > @@ -78,6 +78,12 @@ static inline void paravirt_arch_exit_mmap(struct mm_struct *mm)
> >   	PVOP_VCALL1(mmu.exit_mmap, mm);
> >   }
> > +static inline void page_encryption_changed(unsigned long vaddr, int npages,
> > +						bool enc)
> > +{
> > +	PVOP_VCALL3(mmu.page_encryption_changed, vaddr, npages, enc);
> > +}
> > +
> >   #ifdef CONFIG_PARAVIRT_XXL
> >   static inline void load_sp0(unsigned long sp0)
> >   {
> > @@ -946,6 +952,10 @@ static inline void paravirt_arch_dup_mmap(struct mm_struct *oldmm,
> >   static inline void paravirt_arch_exit_mmap(struct mm_struct *mm)
> >   {
> >   }
> > +
> > +static inline void page_encryption_changed(unsigned long vaddr, int npages, bool enc)
> > +{
> > +}
> >   #endif
> >   #endif /* __ASSEMBLY__ */
> >   #endif /* _ASM_X86_PARAVIRT_H */
> > diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
> > index 732f62e04ddb..03bfd515c59c 100644
> > --- a/arch/x86/include/asm/paravirt_types.h
> > +++ b/arch/x86/include/asm/paravirt_types.h
> > @@ -215,6 +215,8 @@ struct pv_mmu_ops {
> >   	/* Hook for intercepting the destruction of an mm_struct. */
> >   	void (*exit_mmap)(struct mm_struct *mm);
> > +	void (*page_encryption_changed)(unsigned long vaddr, int npages,
> > +					bool enc);
> >   #ifdef CONFIG_PARAVIRT_XXL
> >   	struct paravirt_callee_save read_cr2;
> > diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
> > index c131ba4e70ef..840c02b23aeb 100644
> > --- a/arch/x86/kernel/paravirt.c
> > +++ b/arch/x86/kernel/paravirt.c
> > @@ -367,6 +367,7 @@ struct paravirt_patch_template pv_ops = {
> >   			(void (*)(struct mmu_gather *, void *))tlb_remove_page,
> >   	.mmu.exit_mmap		= paravirt_nop,
> > +	.mmu.page_encryption_changed	= paravirt_nop,
> >   #ifdef CONFIG_PARAVIRT_XXL
> >   	.mmu.read_cr2		= __PV_IS_CALLEE_SAVE(native_read_cr2),
> > diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
> > index f4bd4b431ba1..c9800fa811f6 100644
> > --- a/arch/x86/mm/mem_encrypt.c
> > +++ b/arch/x86/mm/mem_encrypt.c
> > @@ -19,6 +19,7 @@
> >   #include <linux/kernel.h>
> >   #include <linux/bitops.h>
> >   #include <linux/dma-mapping.h>
> > +#include <linux/kvm_para.h>
> >   #include <asm/tlbflush.h>
> >   #include <asm/fixmap.h>
> > @@ -29,6 +30,7 @@
> >   #include <asm/processor-flags.h>
> >   #include <asm/msr.h>
> >   #include <asm/cmdline.h>
> > +#include <asm/kvm_para.h>
> >   #include "mm_internal.h"
> > @@ -196,6 +198,47 @@ void __init sme_early_init(void)
> >   		swiotlb_force = SWIOTLB_FORCE;
> >   }
> > +static void set_memory_enc_dec_hypercall(unsigned long vaddr, int npages,
> > +					bool enc)
> > +{
> > +	unsigned long sz = npages << PAGE_SHIFT;
> > +	unsigned long vaddr_end, vaddr_next;
> > +
> > +	vaddr_end = vaddr + sz;
> > +
> > +	for (; vaddr < vaddr_end; vaddr = vaddr_next) {
> > +		int psize, pmask, level;
> > +		unsigned long pfn;
> > +		pte_t *kpte;
> > +
> > +		kpte = lookup_address(vaddr, &level);
> > +		if (!kpte || pte_none(*kpte))
> > +			return;
> > +
> > +		switch (level) {
> > +		case PG_LEVEL_4K:
> > +			pfn = pte_pfn(*kpte);
> > +			break;
> > +		case PG_LEVEL_2M:
> > +			pfn = pmd_pfn(*(pmd_t *)kpte);
> > +			break;
> > +		case PG_LEVEL_1G:
> > +			pfn = pud_pfn(*(pud_t *)kpte);
> > +			break;
> > +		default:
> > +			return;
> > +		}
> 
> 
> Is it possible to re-use the code in __set_clr_pte_enc() ?
> 
> > +
> > +		psize = page_level_size(level);
> > +		pmask = page_level_mask(level);
> > +
> > +		kvm_sev_hypercall3(KVM_HC_PAGE_ENC_STATUS,
> > +				   pfn << PAGE_SHIFT, psize >> PAGE_SHIFT, enc);
> > +
> > +		vaddr_next = (vaddr & pmask) + psize;
> > +	}
> > +}
> > +
> >   static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc)
> >   {
> >   	pgprot_t old_prot, new_prot;
> > @@ -253,12 +296,13 @@ static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc)
> >   static int __init early_set_memory_enc_dec(unsigned long vaddr,
> >   					   unsigned long size, bool enc)
> >   {
> > -	unsigned long vaddr_end, vaddr_next;
> > +	unsigned long vaddr_end, vaddr_next, start;
> >   	unsigned long psize, pmask;
> >   	int split_page_size_mask;
> >   	int level, ret;
> >   	pte_t *kpte;
> > +	start = vaddr;
> >   	vaddr_next = vaddr;
> >   	vaddr_end = vaddr + size;
> > @@ -313,6 +357,8 @@ static int __init early_set_memory_enc_dec(unsigned long vaddr,
> >   	ret = 0;
> > +	set_memory_enc_dec_hypercall(start, PAGE_ALIGN(size) >> PAGE_SHIFT,
> > +					enc);
> 
> 
> If I haven't missed anything, it seems early_set_memory_encrypted() doesn't
> have a caller. So is there a possibility that we can end up calling it in
> non-SEV context and hence do we need to have the sev_active() guard here ?
> 

As of now early_set_memory_encrypted() is not used, but
early_set_memory_decrypted() is used in __set_percpu_decrypted() and
that is called with the sev_active() check.

Thanks,
Ashish

> >   out:
> >   	__flush_tlb_all();
> >   	return ret;
> > @@ -451,6 +497,15 @@ void __init mem_encrypt_init(void)
> >   	if (sev_active())
> >   		static_branch_enable(&sev_enable_key);
> > +#ifdef CONFIG_PARAVIRT
> > +	/*
> > +	 * With SEV, we need to make a hypercall when page encryption state is
> > +	 * changed.
> > +	 */
> > +	if (sev_active())
> > +		pv_ops.mmu.page_encryption_changed = set_memory_enc_dec_hypercall;
> > +#endif
> > +
> >   	pr_info("AMD %s active\n",
> >   		sev_active() ? "Secure Encrypted Virtualization (SEV)"
> >   			     : "Secure Memory Encryption (SME)");
> > diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
> > index c4aedd00c1ba..86b7804129fc 100644
> > --- a/arch/x86/mm/pat/set_memory.c
> > +++ b/arch/x86/mm/pat/set_memory.c
> > @@ -26,6 +26,7 @@
> >   #include <asm/proto.h>
> >   #include <asm/memtype.h>
> >   #include <asm/set_memory.h>
> > +#include <asm/paravirt.h>
> >   #include "../mm_internal.h"
> > @@ -1987,6 +1988,12 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
> >   	 */
> >   	cpa_flush(&cpa, 0);
> > +	/* Notify hypervisor that a given memory range is mapped encrypted
> > +	 * or decrypted. The hypervisor will use this information during the
> > +	 * VM migration.
> > +	 */
> > +	page_encryption_changed(addr, numpages, enc);
> > +
> >   	return ret;
> >   }
Venu Busireddy April 3, 2020, 9:36 p.m. UTC | #3
On 2020-03-30 06:22:38 +0000, Ashish Kalra wrote:
> From: Brijesh Singh <Brijesh.Singh@amd.com>
> 
> Invoke a hypercall when a memory region is changed from encrypted ->
> decrypted and vice versa. Hypervisor need to know the page encryption
s/need/needs/
> status during the guest migration.
> 
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: "Radim Krčmář" <rkrcmar@redhat.com>
> Cc: Joerg Roedel <joro@8bytes.org>
> Cc: Borislav Petkov <bp@suse.de>
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Cc: x86@kernel.org
> Cc: kvm@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>

Reviewed-by: Venu Busireddy <venu.busireddy@oracle.com>

> ---
>  arch/x86/include/asm/paravirt.h       | 10 +++++
>  arch/x86/include/asm/paravirt_types.h |  2 +
>  arch/x86/kernel/paravirt.c            |  1 +
>  arch/x86/mm/mem_encrypt.c             | 57 ++++++++++++++++++++++++++-
>  arch/x86/mm/pat/set_memory.c          |  7 ++++
>  5 files changed, 76 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
> index 694d8daf4983..8127b9c141bf 100644
> --- a/arch/x86/include/asm/paravirt.h
> +++ b/arch/x86/include/asm/paravirt.h
> @@ -78,6 +78,12 @@ static inline void paravirt_arch_exit_mmap(struct mm_struct *mm)
>  	PVOP_VCALL1(mmu.exit_mmap, mm);
>  }
>  
> +static inline void page_encryption_changed(unsigned long vaddr, int npages,
> +						bool enc)
> +{
> +	PVOP_VCALL3(mmu.page_encryption_changed, vaddr, npages, enc);
> +}
> +
>  #ifdef CONFIG_PARAVIRT_XXL
>  static inline void load_sp0(unsigned long sp0)
>  {
> @@ -946,6 +952,10 @@ static inline void paravirt_arch_dup_mmap(struct mm_struct *oldmm,
>  static inline void paravirt_arch_exit_mmap(struct mm_struct *mm)
>  {
>  }
> +
> +static inline void page_encryption_changed(unsigned long vaddr, int npages, bool enc)
> +{
> +}
>  #endif
>  #endif /* __ASSEMBLY__ */
>  #endif /* _ASM_X86_PARAVIRT_H */
> diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
> index 732f62e04ddb..03bfd515c59c 100644
> --- a/arch/x86/include/asm/paravirt_types.h
> +++ b/arch/x86/include/asm/paravirt_types.h
> @@ -215,6 +215,8 @@ struct pv_mmu_ops {
>  
>  	/* Hook for intercepting the destruction of an mm_struct. */
>  	void (*exit_mmap)(struct mm_struct *mm);
> +	void (*page_encryption_changed)(unsigned long vaddr, int npages,
> +					bool enc);
>  
>  #ifdef CONFIG_PARAVIRT_XXL
>  	struct paravirt_callee_save read_cr2;
> diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
> index c131ba4e70ef..840c02b23aeb 100644
> --- a/arch/x86/kernel/paravirt.c
> +++ b/arch/x86/kernel/paravirt.c
> @@ -367,6 +367,7 @@ struct paravirt_patch_template pv_ops = {
>  			(void (*)(struct mmu_gather *, void *))tlb_remove_page,
>  
>  	.mmu.exit_mmap		= paravirt_nop,
> +	.mmu.page_encryption_changed	= paravirt_nop,
>  
>  #ifdef CONFIG_PARAVIRT_XXL
>  	.mmu.read_cr2		= __PV_IS_CALLEE_SAVE(native_read_cr2),
> diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
> index f4bd4b431ba1..c9800fa811f6 100644
> --- a/arch/x86/mm/mem_encrypt.c
> +++ b/arch/x86/mm/mem_encrypt.c
> @@ -19,6 +19,7 @@
>  #include <linux/kernel.h>
>  #include <linux/bitops.h>
>  #include <linux/dma-mapping.h>
> +#include <linux/kvm_para.h>
>  
>  #include <asm/tlbflush.h>
>  #include <asm/fixmap.h>
> @@ -29,6 +30,7 @@
>  #include <asm/processor-flags.h>
>  #include <asm/msr.h>
>  #include <asm/cmdline.h>
> +#include <asm/kvm_para.h>
>  
>  #include "mm_internal.h"
>  
> @@ -196,6 +198,47 @@ void __init sme_early_init(void)
>  		swiotlb_force = SWIOTLB_FORCE;
>  }
>  
> +static void set_memory_enc_dec_hypercall(unsigned long vaddr, int npages,
> +					bool enc)
> +{
> +	unsigned long sz = npages << PAGE_SHIFT;
> +	unsigned long vaddr_end, vaddr_next;
> +
> +	vaddr_end = vaddr + sz;
> +
> +	for (; vaddr < vaddr_end; vaddr = vaddr_next) {
> +		int psize, pmask, level;
> +		unsigned long pfn;
> +		pte_t *kpte;
> +
> +		kpte = lookup_address(vaddr, &level);
> +		if (!kpte || pte_none(*kpte))
> +			return;
> +
> +		switch (level) {
> +		case PG_LEVEL_4K:
> +			pfn = pte_pfn(*kpte);
> +			break;
> +		case PG_LEVEL_2M:
> +			pfn = pmd_pfn(*(pmd_t *)kpte);
> +			break;
> +		case PG_LEVEL_1G:
> +			pfn = pud_pfn(*(pud_t *)kpte);
> +			break;
> +		default:
> +			return;
> +		}
> +
> +		psize = page_level_size(level);
> +		pmask = page_level_mask(level);
> +
> +		kvm_sev_hypercall3(KVM_HC_PAGE_ENC_STATUS,
> +				   pfn << PAGE_SHIFT, psize >> PAGE_SHIFT, enc);
> +
> +		vaddr_next = (vaddr & pmask) + psize;
> +	}
> +}
> +
>  static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc)
>  {
>  	pgprot_t old_prot, new_prot;
> @@ -253,12 +296,13 @@ static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc)
>  static int __init early_set_memory_enc_dec(unsigned long vaddr,
>  					   unsigned long size, bool enc)
>  {
> -	unsigned long vaddr_end, vaddr_next;
> +	unsigned long vaddr_end, vaddr_next, start;
>  	unsigned long psize, pmask;
>  	int split_page_size_mask;
>  	int level, ret;
>  	pte_t *kpte;
>  
> +	start = vaddr;
>  	vaddr_next = vaddr;
>  	vaddr_end = vaddr + size;
>  
> @@ -313,6 +357,8 @@ static int __init early_set_memory_enc_dec(unsigned long vaddr,
>  
>  	ret = 0;
>  
> +	set_memory_enc_dec_hypercall(start, PAGE_ALIGN(size) >> PAGE_SHIFT,
> +					enc);
>  out:
>  	__flush_tlb_all();
>  	return ret;
> @@ -451,6 +497,15 @@ void __init mem_encrypt_init(void)
>  	if (sev_active())
>  		static_branch_enable(&sev_enable_key);
>  
> +#ifdef CONFIG_PARAVIRT
> +	/*
> +	 * With SEV, we need to make a hypercall when page encryption state is
> +	 * changed.
> +	 */
> +	if (sev_active())
> +		pv_ops.mmu.page_encryption_changed = set_memory_enc_dec_hypercall;
> +#endif
> +
>  	pr_info("AMD %s active\n",
>  		sev_active() ? "Secure Encrypted Virtualization (SEV)"
>  			     : "Secure Memory Encryption (SME)");
> diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
> index c4aedd00c1ba..86b7804129fc 100644
> --- a/arch/x86/mm/pat/set_memory.c
> +++ b/arch/x86/mm/pat/set_memory.c
> @@ -26,6 +26,7 @@
>  #include <asm/proto.h>
>  #include <asm/memtype.h>
>  #include <asm/set_memory.h>
> +#include <asm/paravirt.h>
>  
>  #include "../mm_internal.h"
>  
> @@ -1987,6 +1988,12 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
>  	 */
>  	cpa_flush(&cpa, 0);
>  
> +	/* Notify hypervisor that a given memory range is mapped encrypted
> +	 * or decrypted. The hypervisor will use this information during the
> +	 * VM migration.
> +	 */
> +	page_encryption_changed(addr, numpages, enc);
> +
>  	return ret;
>  }
>  
> -- 
> 2.17.1
>
diff mbox series

Patch

diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 694d8daf4983..8127b9c141bf 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -78,6 +78,12 @@  static inline void paravirt_arch_exit_mmap(struct mm_struct *mm)
 	PVOP_VCALL1(mmu.exit_mmap, mm);
 }
 
+static inline void page_encryption_changed(unsigned long vaddr, int npages,
+						bool enc)
+{
+	PVOP_VCALL3(mmu.page_encryption_changed, vaddr, npages, enc);
+}
+
 #ifdef CONFIG_PARAVIRT_XXL
 static inline void load_sp0(unsigned long sp0)
 {
@@ -946,6 +952,10 @@  static inline void paravirt_arch_dup_mmap(struct mm_struct *oldmm,
 static inline void paravirt_arch_exit_mmap(struct mm_struct *mm)
 {
 }
+
+static inline void page_encryption_changed(unsigned long vaddr, int npages, bool enc)
+{
+}
 #endif
 #endif /* __ASSEMBLY__ */
 #endif /* _ASM_X86_PARAVIRT_H */
diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
index 732f62e04ddb..03bfd515c59c 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -215,6 +215,8 @@  struct pv_mmu_ops {
 
 	/* Hook for intercepting the destruction of an mm_struct. */
 	void (*exit_mmap)(struct mm_struct *mm);
+	void (*page_encryption_changed)(unsigned long vaddr, int npages,
+					bool enc);
 
 #ifdef CONFIG_PARAVIRT_XXL
 	struct paravirt_callee_save read_cr2;
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index c131ba4e70ef..840c02b23aeb 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -367,6 +367,7 @@  struct paravirt_patch_template pv_ops = {
 			(void (*)(struct mmu_gather *, void *))tlb_remove_page,
 
 	.mmu.exit_mmap		= paravirt_nop,
+	.mmu.page_encryption_changed	= paravirt_nop,
 
 #ifdef CONFIG_PARAVIRT_XXL
 	.mmu.read_cr2		= __PV_IS_CALLEE_SAVE(native_read_cr2),
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index f4bd4b431ba1..c9800fa811f6 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -19,6 +19,7 @@ 
 #include <linux/kernel.h>
 #include <linux/bitops.h>
 #include <linux/dma-mapping.h>
+#include <linux/kvm_para.h>
 
 #include <asm/tlbflush.h>
 #include <asm/fixmap.h>
@@ -29,6 +30,7 @@ 
 #include <asm/processor-flags.h>
 #include <asm/msr.h>
 #include <asm/cmdline.h>
+#include <asm/kvm_para.h>
 
 #include "mm_internal.h"
 
@@ -196,6 +198,47 @@  void __init sme_early_init(void)
 		swiotlb_force = SWIOTLB_FORCE;
 }
 
+static void set_memory_enc_dec_hypercall(unsigned long vaddr, int npages,
+					bool enc)
+{
+	unsigned long sz = npages << PAGE_SHIFT;
+	unsigned long vaddr_end, vaddr_next;
+
+	vaddr_end = vaddr + sz;
+
+	for (; vaddr < vaddr_end; vaddr = vaddr_next) {
+		int psize, pmask, level;
+		unsigned long pfn;
+		pte_t *kpte;
+
+		kpte = lookup_address(vaddr, &level);
+		if (!kpte || pte_none(*kpte))
+			return;
+
+		switch (level) {
+		case PG_LEVEL_4K:
+			pfn = pte_pfn(*kpte);
+			break;
+		case PG_LEVEL_2M:
+			pfn = pmd_pfn(*(pmd_t *)kpte);
+			break;
+		case PG_LEVEL_1G:
+			pfn = pud_pfn(*(pud_t *)kpte);
+			break;
+		default:
+			return;
+		}
+
+		psize = page_level_size(level);
+		pmask = page_level_mask(level);
+
+		kvm_sev_hypercall3(KVM_HC_PAGE_ENC_STATUS,
+				   pfn << PAGE_SHIFT, psize >> PAGE_SHIFT, enc);
+
+		vaddr_next = (vaddr & pmask) + psize;
+	}
+}
+
 static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc)
 {
 	pgprot_t old_prot, new_prot;
@@ -253,12 +296,13 @@  static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc)
 static int __init early_set_memory_enc_dec(unsigned long vaddr,
 					   unsigned long size, bool enc)
 {
-	unsigned long vaddr_end, vaddr_next;
+	unsigned long vaddr_end, vaddr_next, start;
 	unsigned long psize, pmask;
 	int split_page_size_mask;
 	int level, ret;
 	pte_t *kpte;
 
+	start = vaddr;
 	vaddr_next = vaddr;
 	vaddr_end = vaddr + size;
 
@@ -313,6 +357,8 @@  static int __init early_set_memory_enc_dec(unsigned long vaddr,
 
 	ret = 0;
 
+	set_memory_enc_dec_hypercall(start, PAGE_ALIGN(size) >> PAGE_SHIFT,
+					enc);
 out:
 	__flush_tlb_all();
 	return ret;
@@ -451,6 +497,15 @@  void __init mem_encrypt_init(void)
 	if (sev_active())
 		static_branch_enable(&sev_enable_key);
 
+#ifdef CONFIG_PARAVIRT
+	/*
+	 * With SEV, we need to make a hypercall when page encryption state is
+	 * changed.
+	 */
+	if (sev_active())
+		pv_ops.mmu.page_encryption_changed = set_memory_enc_dec_hypercall;
+#endif
+
 	pr_info("AMD %s active\n",
 		sev_active() ? "Secure Encrypted Virtualization (SEV)"
 			     : "Secure Memory Encryption (SME)");
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index c4aedd00c1ba..86b7804129fc 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -26,6 +26,7 @@ 
 #include <asm/proto.h>
 #include <asm/memtype.h>
 #include <asm/set_memory.h>
+#include <asm/paravirt.h>
 
 #include "../mm_internal.h"
 
@@ -1987,6 +1988,12 @@  static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
 	 */
 	cpa_flush(&cpa, 0);
 
+	/* Notify hypervisor that a given memory range is mapped encrypted
+	 * or decrypted. The hypervisor will use this information during the
+	 * VM migration.
+	 */
+	page_encryption_changed(addr, numpages, enc);
+
 	return ret;
 }