From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brijesh Singh Subject: [PATCH v12 12/28] sev/i386: register the guest memory range which may contain encrypted data Date: Thu, 8 Mar 2018 06:48:45 -0600 Message-ID: <20180308124901.83533-13-brijesh.singh@amd.com> References: <20180308124901.83533-1-brijesh.singh@amd.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Peter Maydell , Brijesh Singh , kvm@vger.kernel.org, "Michael S. Tsirkin" , Stefan Hajnoczi , Alexander Graf , "Edgar E. Iglesias" , Markus Armbruster , Bruce Rogers , Christian Borntraeger , Marcel Apfelbaum , Borislav Petkov , Thomas Lendacky , Eduardo Habkost , Richard Henderson , "Dr. David Alan Gilbert" , Alistair Francis , Cornelia Huck , Richard Henderson , Peter Crosthwaite , Paolo Bonzini To: qemu-devel@nongnu.org Return-path: In-Reply-To: <20180308124901.83533-1-brijesh.singh@amd.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel2=m.gmane.org@nongnu.org Sender: "Qemu-devel" List-Id: kvm.vger.kernel.org When SEV is enabled, the hardware encryption engine uses a tweak such that the two identical plaintext at different location will have a different ciphertexts. So swapping or moving a ciphertexts of two guest pages will not result in plaintexts being swapped. Hence relocating a physical backing pages of the SEV guest will require some additional steps in KVM driver. The KVM_MEMORY_ENCRYPT_{UN,}REG_REGION ioctl can be used to register/unregister the guest memory region which may contain the encrypted data. KVM driver will internally handle the relocating physical backing pages of registered memory regions. Cc: Paolo Bonzini Cc: Richard Henderson Cc: Eduardo Habkost Signed-off-by: Brijesh Singh --- target/i386/sev.c | 42 ++++++++++++++++++++++++++++++++++++++++++ target/i386/trace-events | 2 ++ 2 files changed, 44 insertions(+) diff --git a/target/i386/sev.c b/target/i386/sev.c index 288612e1aa46..4f85035d5203 100644 --- a/target/i386/sev.c +++ b/target/i386/sev.c @@ -105,6 +105,46 @@ fw_error_to_str(int code) return sev_fw_errlist[code]; } +static void +sev_ram_block_added(RAMBlockNotifier *n, void *host, size_t size) +{ + int r; + struct kvm_enc_region range; + + range.addr = (__u64)host; + range.size = size; + + trace_kvm_memcrypt_register_region(host, size); + r = kvm_vm_ioctl(kvm_state, KVM_MEMORY_ENCRYPT_REG_REGION, &range); + if (r) { + error_report("%s: failed to register region (%p+%#lx) error '%s'", + __func__, host, size, strerror(errno)); + exit(1); + } +} + +static void +sev_ram_block_removed(RAMBlockNotifier *n, void *host, size_t size) +{ + int r; + struct kvm_enc_region range; + + range.addr = (__u64)host; + range.size = size; + + trace_kvm_memcrypt_unregister_region(host, size); + r = kvm_vm_ioctl(kvm_state, KVM_MEMORY_ENCRYPT_UNREG_REGION, &range); + if (r) { + error_report("%s: failed to unregister region (%p+%#lx)", + __func__, host, size); + } +} + +static struct RAMBlockNotifier sev_ram_notifier = { + .ram_block_added = sev_ram_block_added, + .ram_block_removed = sev_ram_block_removed, +}; + static void qsev_guest_finalize(Object *obj) { @@ -436,6 +476,8 @@ sev_guest_init(const char *id) goto err; } + ram_block_notifier_add(&sev_ram_notifier); + return s; err: g_free(sev_state); diff --git a/target/i386/trace-events b/target/i386/trace-events index 797b716751b7..ffa3d2250425 100644 --- a/target/i386/trace-events +++ b/target/i386/trace-events @@ -8,3 +8,5 @@ kvm_x86_update_msi_routes(int num) "Updated %d MSI routes" # target/i386/sev.c kvm_sev_init(void) "" +kvm_memcrypt_register_region(void *addr, size_t len) "addr %p len 0x%lu" +kvm_memcrypt_unregister_region(void *addr, size_t len) "addr %p len 0x%lu" -- 2.14.3