From: Tianyu Lan <ltykernel@gmail.com>
To: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org,
decui@microsoft.com, tglx@linutronix.de, mingo@redhat.com,
bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org,
hpa@zytor.com, daniel.lezcano@linaro.org, arnd@arndb.de,
michael.h.kelley@microsoft.com
Cc: Tianyu Lan <tiala@microsoft.com>,
linux-arch@vger.kernel.org, linux-hyperv@vger.kernel.org,
linux-kernel@vger.kernel.org, vkuznets@redhat.com
Subject: [PATCH V2 4/9] drivers: hv: Mark percpu hvcall input arg page unencrypted in SEV-SNP enlightened guest
Date: Mon, 26 Jun 2023 23:22:42 -0400 [thread overview]
Message-ID: <20230627032248.2170007-5-ltykernel@gmail.com> (raw)
In-Reply-To: <20230627032248.2170007-1-ltykernel@gmail.com>
From: Tianyu Lan <tiala@microsoft.com>
Hypervisor needs to access input arg, VMBus synic event and
message pages. Mark these pages unencrypted in the SEV-SNP
guest and free them only if they have been marked encrypted
successfully.
Signed-off-by: Tianyu Lan <tiala@microsoft.com>
---
drivers/hv/hv.c | 57 +++++++++++++++++++++++++++++++++++++++---
drivers/hv/hv_common.c | 13 ++++++++++
2 files changed, 67 insertions(+), 3 deletions(-)
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index de6708dbe0df..ec6e35a0d9bf 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -20,6 +20,7 @@
#include <linux/interrupt.h>
#include <clocksource/hyperv_timer.h>
#include <asm/mshyperv.h>
+#include <linux/set_memory.h>
#include "hyperv_vmbus.h"
/* The one and only */
@@ -78,7 +79,7 @@ int hv_post_message(union hv_connection_id connection_id,
int hv_synic_alloc(void)
{
- int cpu;
+ int cpu, ret = -ENOMEM;
struct hv_per_cpu_context *hv_cpu;
/*
@@ -123,26 +124,76 @@ int hv_synic_alloc(void)
goto err;
}
}
+
+ if (hv_isolation_type_en_snp()) {
+ ret = set_memory_decrypted((unsigned long)
+ hv_cpu->synic_message_page, 1);
+ if (ret) {
+ pr_err("Failed to decrypt SYNIC msg page: %d\n", ret);
+ hv_cpu->synic_message_page = NULL;
+
+ /*
+ * Free the event page here so that hv_synic_free()
+ * won't later try to re-encrypt it.
+ */
+ free_page((unsigned long)hv_cpu->synic_event_page);
+ hv_cpu->synic_event_page = NULL;
+ goto err;
+ }
+
+ ret = set_memory_decrypted((unsigned long)
+ hv_cpu->synic_event_page, 1);
+ if (ret) {
+ pr_err("Failed to decrypt SYNIC event page: %d\n", ret);
+ hv_cpu->synic_event_page = NULL;
+ goto err;
+ }
+
+ memset(hv_cpu->synic_message_page, 0, PAGE_SIZE);
+ memset(hv_cpu->synic_event_page, 0, PAGE_SIZE);
+ }
}
return 0;
+
err:
/*
* Any memory allocations that succeeded will be freed when
* the caller cleans up by calling hv_synic_free()
*/
- return -ENOMEM;
+ return ret;
}
void hv_synic_free(void)
{
- int cpu;
+ int cpu, ret;
for_each_present_cpu(cpu) {
struct hv_per_cpu_context *hv_cpu
= per_cpu_ptr(hv_context.cpu_context, cpu);
+ /* It's better to leak the page if the encryption fails. */
+ if (hv_isolation_type_en_snp()) {
+ if (hv_cpu->synic_message_page) {
+ ret = set_memory_encrypted((unsigned long)
+ hv_cpu->synic_message_page, 1);
+ if (ret) {
+ pr_err("Failed to encrypt SYNIC msg page: %d\n", ret);
+ hv_cpu->synic_message_page = NULL;
+ }
+ }
+
+ if (hv_cpu->synic_event_page) {
+ ret = set_memory_encrypted((unsigned long)
+ hv_cpu->synic_event_page, 1);
+ if (ret) {
+ pr_err("Failed to encrypt SYNIC event page: %d\n", ret);
+ hv_cpu->synic_event_page = NULL;
+ }
+ }
+ }
+
free_page((unsigned long)hv_cpu->synic_event_page);
free_page((unsigned long)hv_cpu->synic_message_page);
}
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index 4b4aa53c34c2..2d43ba2bc925 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -24,6 +24,7 @@
#include <linux/kmsg_dump.h>
#include <linux/slab.h>
#include <linux/dma-map-ops.h>
+#include <linux/set_memory.h>
#include <asm/hyperv-tlfs.h>
#include <asm/mshyperv.h>
@@ -359,6 +360,7 @@ int hv_common_cpu_init(unsigned int cpu)
u64 msr_vp_index;
gfp_t flags;
int pgcount = hv_root_partition ? 2 : 1;
+ int ret;
/* hv_cpu_init() can be called with IRQs disabled from hv_resume() */
flags = irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL;
@@ -378,6 +380,17 @@ int hv_common_cpu_init(unsigned int cpu)
outputarg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg);
*outputarg = (char *)(*inputarg) + HV_HYP_PAGE_SIZE;
}
+
+ if (hv_isolation_type_en_snp()) {
+ ret = set_memory_decrypted((unsigned long)*inputarg, pgcount);
+ if (ret) {
+ kfree(*inputarg);
+ *inputarg = NULL;
+ return ret;
+ }
+
+ memset(*inputarg, 0x00, pgcount * PAGE_SIZE);
+ }
}
msr_vp_index = hv_get_register(HV_REGISTER_VP_INDEX);
--
2.25.1
next prev parent reply other threads:[~2023-06-27 3:28 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-27 3:22 [PATCH V2 0/9] x86/hyperv: Add AMD sev-snp enlightened guest support on hyperv Tianyu Lan
2023-06-27 3:22 ` [PATCH V2 1/9] x86/hyperv: Add sev-snp enlightened guest static key Tianyu Lan
2023-07-04 14:17 ` Michael Kelley (LINUX)
2023-07-05 14:43 ` Tianyu Lan
2023-06-27 3:22 ` [PATCH V2 2/9] x86/hyperv: Set Virtual Trust Level in VMBus init message Tianyu Lan
2023-07-04 14:18 ` Michael Kelley (LINUX)
2023-07-07 9:07 ` [EXTERNAL] " Saurabh Singh Sengar
2023-08-07 4:48 ` Wei Liu
2023-08-10 16:22 ` Tianyu Lan
2023-08-11 2:55 ` Saurabh Singh Sengar
2023-06-27 3:22 ` [PATCH V2 3/9] x86/hyperv: Mark Hyper-V vp assist page unencrypted in SEV-SNP enlightened guest Tianyu Lan
2023-07-04 14:18 ` Michael Kelley (LINUX)
2023-06-27 3:22 ` Tianyu Lan [this message]
2023-07-04 14:19 ` [PATCH V2 4/9] drivers: hv: Mark percpu hvcall input arg " Michael Kelley (LINUX)
2023-06-27 3:22 ` [PATCH V2 5/9] x86/hyperv: Use vmmcall to implement Hyper-V hypercall in sev-snp " Tianyu Lan
2023-06-27 3:22 ` [PATCH V2 6/9] clocksource: hyper-v: Mark hyperv tsc page unencrypted " Tianyu Lan
2023-07-04 14:19 ` Michael Kelley (LINUX)
2023-06-27 3:22 ` [PATCH V2 7/9] x86/hyperv: Initialize cpu and memory for SEV-SNP " Tianyu Lan
2023-07-04 14:23 ` Michael Kelley (LINUX)
2023-06-27 3:22 ` [PATCH V2 8/9] x86/hyperv: Add smp support for SEV-SNP guest Tianyu Lan
2023-07-04 14:24 ` Michael Kelley (LINUX)
2023-06-27 3:22 ` [PATCH V2 9/9] x86/hyperv: Add hyperv-specific handling for VMMCALL under SEV-ES Tianyu Lan
2023-07-04 14:25 ` Michael Kelley (LINUX)
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