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From: Borislav Petkov <bp@suse.de>
To: "Singh, Brijesh" <brijesh.singh@amd.com>
Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"Thomas Gleixner" <tglx@linutronix.de>,
	"Ingo Molnar" <mingo@redhat.com>,
	"H. Peter Anvin" <hpa@zytor.com>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>,
	"Joerg Roedel" <joro@8bytes.org>,
	"Lendacky, Thomas" <Thomas.Lendacky@amd.com>,
	"x86@kernel.org" <x86@kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3 10/11] mm: x86: Invoke hypercall when page encryption status is changed
Date: Thu, 29 Aug 2019 18:52:18 +0200	[thread overview]
Message-ID: <20190829165218.GD2132@zn.tnic> (raw)
In-Reply-To: <20190710201244.25195-11-brijesh.singh@amd.com>

On Wed, Jul 10, 2019 at 08:13:11PM +0000, Singh, Brijesh wrote:

> Subject: Re: [PATCH v3 10/11] mm: x86: Invoke hypercall when page encryption status is changed

Subject prefix: "x86/mm: Invoke ..."

git log <filename> would usually show you how the prefixing should look
like.

> 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>
> ---
>  arch/x86/include/asm/mem_encrypt.h |  3 ++
>  arch/x86/mm/mem_encrypt.c          | 45 +++++++++++++++++++++++++++++-
>  arch/x86/mm/pageattr.c             | 15 ++++++++++
>  3 files changed, 62 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h
> index 0c196c47d621..6e654ab5a8e4 100644
> --- a/arch/x86/include/asm/mem_encrypt.h
> +++ b/arch/x86/include/asm/mem_encrypt.h
> @@ -94,4 +94,7 @@ extern char __start_bss_decrypted[], __end_bss_decrypted[], __start_bss_decrypte
>  
>  #endif	/* __ASSEMBLY__ */
>  
> +extern void set_memory_enc_dec_hypercall(unsigned long vaddr,
> +					 unsigned long size, bool enc);
> +
>  #endif	/* __X86_MEM_ENCRYPT_H__ */
> diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
> index e0df96fdfe46..f3fda1de2869 100644
> --- a/arch/x86/mm/mem_encrypt.c
> +++ b/arch/x86/mm/mem_encrypt.c
> @@ -15,6 +15,7 @@
>  #include <linux/dma-direct.h>
>  #include <linux/swiotlb.h>
>  #include <linux/mem_encrypt.h>
> +#include <linux/kvm_para.h>
>  
>  #include <asm/tlbflush.h>
>  #include <asm/fixmap.h>
> @@ -25,6 +26,7 @@
>  #include <asm/processor-flags.h>
>  #include <asm/msr.h>
>  #include <asm/cmdline.h>
> +#include <asm/kvm_para.h>
>  
>  #include "mm_internal.h"
>  
> @@ -192,6 +194,45 @@ void __init sme_early_init(void)
>  		swiotlb_force = SWIOTLB_FORCE;
>  }
>  
> +void set_memory_enc_dec_hypercall(unsigned long vaddr, unsigned long sz, bool enc)
> +{
> +	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;
> @@ -249,12 +290,13 @@ 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;
>  
> @@ -309,6 +351,7 @@ static int __init early_set_memory_enc_dec(unsigned long vaddr,
>  
>  	ret = 0;
>  
> +	set_memory_enc_dec_hypercall(start, size, enc);

That function iterates the same way over the virtual addresses as
early_set_memory_enc_dec() does. Please call kvm_sev_hypercall3(),
wrapped of course, directly from early_set_memory_enc_dec(), for
each iteration of the loop instead of iterating over all the virtual
addresses a second time in set_memory_enc_dec_hypercall().

-- 
Regards/Gruss,
    Boris.

SUSE Software Solutions Germany GmbH, GF: Felix Imendörffer, HRB 247165, AG München

  reply	other threads:[~2019-08-29 16:52 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-10 20:12 [PATCH v3 00/11] Add AMD SEV guest live migration support Singh, Brijesh
2019-07-10 20:13 ` [PATCH v3 01/11] KVM: SVM: Add KVM_SEV SEND_START command Singh, Brijesh
2019-08-22 10:08   ` Borislav Petkov
2019-08-22 13:23     ` Singh, Brijesh
2019-11-12 18:35   ` Peter Gonda
2019-11-12 22:27     ` Brijesh Singh
2019-11-14 19:27       ` Peter Gonda
2019-11-19 14:06         ` Brijesh Singh
2019-07-10 20:13 ` [PATCH v3 02/11] KVM: SVM: Add KVM_SEND_UPDATE_DATA command Singh, Brijesh
2019-08-22 12:02   ` Borislav Petkov
2019-08-22 13:27     ` Singh, Brijesh
2019-08-22 13:34       ` Borislav Petkov
2019-11-12 22:23   ` Peter Gonda
2019-07-10 20:13 ` [PATCH v3 03/11] KVM: SVM: Add KVM_SEV_SEND_FINISH command Singh, Brijesh
2019-08-26 13:29   ` Borislav Petkov
2019-07-10 20:13 ` [PATCH v3 04/11] KVM: SVM: Add support for KVM_SEV_RECEIVE_START command Singh, Brijesh
2019-07-10 20:13 ` [PATCH v3 05/11] KVM: SVM: Add KVM_SEV_RECEIVE_UPDATE_DATA command Singh, Brijesh
2019-08-27 12:09   ` Borislav Petkov
2019-11-14 21:02   ` Peter Gonda
2019-07-10 20:13 ` [PATCH v3 06/11] KVM: SVM: Add KVM_SEV_RECEIVE_FINISH command Singh, Brijesh
2019-08-27 12:19   ` Borislav Petkov
2019-07-10 20:13 ` [PATCH v3 07/11] KVM: x86: Add AMD SEV specific Hypercall3 Singh, Brijesh
2019-07-10 20:13 ` [PATCH v3 08/11] KVM: X86: Introduce KVM_HC_PAGE_ENC_STATUS hypercall Singh, Brijesh
2019-07-21 20:57   ` David Rientjes
2019-07-22 17:12     ` Cfir Cohen
2019-07-23 15:31       ` Singh, Brijesh
2019-07-23 15:16     ` Singh, Brijesh
2019-11-25 19:07   ` Peter Gonda
2019-07-10 20:13 ` [PATCH v3 09/11] KVM: x86: Introduce KVM_GET_PAGE_ENC_BITMAP ioctl Singh, Brijesh
2019-08-29 16:26   ` Borislav Petkov
2019-08-29 16:41     ` Singh, Brijesh
2019-08-29 16:56       ` Borislav Petkov
2019-07-10 20:13 ` [PATCH v3 10/11] mm: x86: Invoke hypercall when page encryption status is changed Singh, Brijesh
2019-08-29 16:52   ` Borislav Petkov [this message]
2019-08-29 18:07   ` Borislav Petkov
2019-08-29 18:21     ` Thomas Gleixner
2019-08-29 18:32       ` Thomas Gleixner
2019-07-10 20:13 ` [PATCH v3 11/11] KVM: x86: Introduce KVM_SET_PAGE_ENC_BITMAP ioctl Singh, Brijesh
2019-11-15  1:22   ` Steve Rutherford
2019-11-15  1:39     ` Steve Rutherford
2019-07-12 15:52 ` [PATCH v3 00/11] Add AMD SEV guest live migration support Konrad Rzeszutek Wilk
2019-07-12 16:31   ` Singh, Brijesh

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