From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To: Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Sean Christopherson <seanjc@google.com>,
Jim Mattson <jmattson@google.com>
Cc: David Rientjes <rientjes@google.com>,
"Edgecombe, Rick P" <rick.p.edgecombe@intel.com>,
"Kleen, Andi" <andi.kleen@intel.com>,
"Yamahata, Isaku" <isaku.yamahata@intel.com>,
Erdem Aktas <erdemaktas@google.com>,
Steve Rutherford <srutherford@google.com>,
Peter Gonda <pgonda@google.com>,
David Hildenbrand <david@redhat.com>,
x86@kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: [RFCv2 03/13] x86/kvm: Make DMA pages shared
Date: Fri, 16 Apr 2021 18:40:56 +0300 [thread overview]
Message-ID: <20210416154106.23721-4-kirill.shutemov@linux.intel.com> (raw)
In-Reply-To: <20210416154106.23721-1-kirill.shutemov@linux.intel.com>
Make force_dma_unencrypted() return true for KVM to get DMA pages mapped
as shared.
__set_memory_enc_dec() now informs the host via hypercall if the state
of the page has changed from shared to private or back.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
arch/x86/Kconfig | 1 +
arch/x86/mm/mem_encrypt_common.c | 5 +++--
arch/x86/mm/pat/set_memory.c | 10 ++++++++++
include/uapi/linux/kvm_para.h | 1 +
4 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 2b4ce1722dbd..d197b3beb904 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -811,6 +811,7 @@ config KVM_GUEST
select PARAVIRT_CLOCK
select ARCH_CPUIDLE_HALTPOLL
select X86_HV_CALLBACK_VECTOR
+ select X86_MEM_ENCRYPT_COMMON
default y
help
This option enables various optimizations for running under the KVM
diff --git a/arch/x86/mm/mem_encrypt_common.c b/arch/x86/mm/mem_encrypt_common.c
index dd791352f73f..6bf0718bb72a 100644
--- a/arch/x86/mm/mem_encrypt_common.c
+++ b/arch/x86/mm/mem_encrypt_common.c
@@ -10,14 +10,15 @@
#include <linux/mm.h>
#include <linux/mem_encrypt.h>
#include <linux/dma-direct.h>
+#include <asm/kvm_para.h>
/* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */
bool force_dma_unencrypted(struct device *dev)
{
/*
- * For SEV, all DMA must be to unencrypted/shared addresses.
+ * For SEV and KVM, all DMA must be to unencrypted/shared addresses.
*/
- if (sev_active())
+ if (sev_active() || kvm_mem_protected())
return true;
/*
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index 16f878c26667..4b312d80033d 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -16,6 +16,7 @@
#include <linux/pci.h>
#include <linux/vmalloc.h>
#include <linux/libnvdimm.h>
+#include <linux/kvm_para.h>
#include <asm/e820/api.h>
#include <asm/processor.h>
@@ -1977,6 +1978,15 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
struct cpa_data cpa;
int ret;
+ if (kvm_mem_protected()) {
+ /* TODO: Unsharing memory back */
+ if (WARN_ON_ONCE(enc))
+ return -ENOSYS;
+
+ return kvm_hypercall2(KVM_HC_MEM_SHARE,
+ __pa(addr) >> PAGE_SHIFT, numpages);
+ }
+
/* Nothing to do if memory encryption is not active */
if (!mem_encrypt_active())
return 0;
diff --git a/include/uapi/linux/kvm_para.h b/include/uapi/linux/kvm_para.h
index 1a216f32e572..09d36683ee0a 100644
--- a/include/uapi/linux/kvm_para.h
+++ b/include/uapi/linux/kvm_para.h
@@ -30,6 +30,7 @@
#define KVM_HC_SEND_IPI 10
#define KVM_HC_SCHED_YIELD 11
#define KVM_HC_ENABLE_MEM_PROTECTED 12
+#define KVM_HC_MEM_SHARE 13
/*
* hypercalls use architecture specific
--
2.26.3
next prev parent reply other threads:[~2021-04-16 15:41 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-16 15:40 [RFCv2 00/13] TDX and guest memory unmapping Kirill A. Shutemov
2021-04-16 15:40 ` [RFCv2 01/13] x86/mm: Move force_dma_unencrypted() to common code Kirill A. Shutemov
2021-04-16 15:40 ` [RFCv2 02/13] x86/kvm: Introduce KVM memory protection feature Kirill A. Shutemov
2021-04-16 16:10 ` Borislav Petkov
2021-04-19 10:10 ` Kirill A. Shutemov
2021-04-16 15:40 ` Kirill A. Shutemov [this message]
2021-04-16 15:40 ` [RFCv2 04/13] x86/kvm: Use bounce buffers for KVM memory protection Kirill A. Shutemov
2021-04-16 16:21 ` Dave Hansen
2021-04-16 15:40 ` [RFCv2 05/13] x86/kvmclock: Share hvclock memory with the host Kirill A. Shutemov
2021-04-16 15:40 ` [RFCv2 06/13] x86/realmode: Share trampoline area if KVM memory protection enabled Kirill A. Shutemov
2021-04-19 16:49 ` Dave Hansen
2021-04-16 15:41 ` [RFCv2 07/13] mm: Add hwpoison_entry_to_pfn() and hwpoison_entry_to_page() Kirill A. Shutemov
2021-04-16 15:41 ` [RFCv2 08/13] mm/gup: Add FOLL_ALLOW_POISONED Kirill A. Shutemov
2021-04-16 15:41 ` [RFCv2 09/13] shmem: Fail shmem_getpage_gfp() on poisoned pages Kirill A. Shutemov
2021-04-16 15:41 ` [RFCv2 10/13] mm: Keep page reference for hwpoison entries Kirill A. Shutemov
2021-04-16 15:41 ` [RFCv2 11/13] mm: Replace hwpoison entry with present PTE if page got unpoisoned Kirill A. Shutemov
2021-04-16 15:41 ` [RFCv2 12/13] KVM: passdown struct kvm to hva_to_pfn_slow() Kirill A. Shutemov
2021-04-16 15:41 ` [RFCv2 13/13] KVM: unmap guest memory using poisoned pages Kirill A. Shutemov
2021-04-16 17:30 ` Sean Christopherson
2021-04-19 11:32 ` Xiaoyao Li
2021-04-19 14:26 ` Kirill A. Shutemov
2021-04-19 16:01 ` Sean Christopherson
2021-04-19 16:40 ` Kirill A. Shutemov
2021-04-19 18:09 ` Sean Christopherson
2021-04-19 18:12 ` David Hildenbrand
2021-04-19 18:53 ` Kirill A. Shutemov
2021-04-19 20:09 ` Sean Christopherson
2021-04-19 22:57 ` Kirill A. Shutemov
2021-04-20 17:13 ` Sean Christopherson
2021-05-21 12:31 ` Kirill A. Shutemov
2021-05-26 19:46 ` Sean Christopherson
2021-05-31 20:07 ` Kirill A. Shutemov
2021-06-02 17:51 ` Sean Christopherson
2021-06-02 23:33 ` Kirill A. Shutemov
2021-06-03 19:46 ` Sean Christopherson
2021-06-04 14:29 ` Kirill A. Shutemov
2021-06-04 17:16 ` Andy Lutomirski
2021-06-04 17:54 ` Kirill A. Shutemov
2021-04-16 16:46 ` [RFCv2 00/13] TDX and guest memory unmapping Matthew Wilcox
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