All of lore.kernel.org
 help / color / mirror / Atom feed
From: "tip-bot2 for Tianyu Lan" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Tianyu Lan <Tianyu.Lan@microsoft.com>,
	Borislav Petkov <bp@suse.de>,
	Michael Kelley <mikelley@microsoft.com>,
	x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [tip: x86/sev] x86/sev: Expose sev_es_ghcb_hv_call() for use by HyperV
Date: Mon, 25 Oct 2021 16:34:26 -0000	[thread overview]
Message-ID: <163517966616.626.15035578353013624242.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20211025122116.264793-6-ltykernel@gmail.com>

The following commit has been merged into the x86/sev branch of tip:

Commit-ID:     007faec014cb5d26983c1f86fd08c6539b41392e
Gitweb:        https://git.kernel.org/tip/007faec014cb5d26983c1f86fd08c6539b41392e
Author:        Tianyu Lan <Tianyu.Lan@microsoft.com>
AuthorDate:    Mon, 25 Oct 2021 08:21:10 -04:00
Committer:     Borislav Petkov <bp@suse.de>
CommitterDate: Mon, 25 Oct 2021 18:11:42 +02:00

x86/sev: Expose sev_es_ghcb_hv_call() for use by HyperV

Hyper-V needs to issue the GHCB HV call in order to read/write MSRs in
Isolation VMs. For that, expose sev_es_ghcb_hv_call().

The Hyper-V Isolation VMs are unenlightened guests and run a paravisor
at VMPL0 for communicating. GHCB pages are being allocated and set up
by that paravisor. Linux gets the GHCB page's physical address via
MSR_AMD64_SEV_ES_GHCB from the paravisor and should not change it.

Add a @set_ghcb_msr parameter to sev_es_ghcb_hv_call() to control
whether the function should set the GHCB's address prior to the call or
not and export that function for use by HyperV.

  [ bp: - Massage commit message
        - add a struct ghcb forward declaration to fix randconfig builds. ]

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20211025122116.264793-6-ltykernel@gmail.com
---
 arch/x86/include/asm/sev.h   |  6 ++++++
 arch/x86/kernel/sev-shared.c | 25 ++++++++++++++++---------
 arch/x86/kernel/sev.c        | 13 +++++++------
 3 files changed, 29 insertions(+), 15 deletions(-)

diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index fa5cd05..ec060c4 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -53,6 +53,7 @@ static inline u64 lower_bits(u64 val, unsigned int bits)
 
 struct real_mode_header;
 enum stack_type;
+struct ghcb;
 
 /* Early IDT entry points for #VC handler */
 extern void vc_no_ghcb(void);
@@ -81,6 +82,11 @@ static __always_inline void sev_es_nmi_complete(void)
 		__sev_es_nmi_complete();
 }
 extern int __init sev_es_efi_map_ghcbs(pgd_t *pgd);
+extern enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
+					  bool set_ghcb_msr,
+					  struct es_em_ctxt *ctxt,
+					  u64 exit_code, u64 exit_info_1,
+					  u64 exit_info_2);
 #else
 static inline void sev_es_ist_enter(struct pt_regs *regs) { }
 static inline void sev_es_ist_exit(void) { }
diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c
index 4579c38..0aacd60 100644
--- a/arch/x86/kernel/sev-shared.c
+++ b/arch/x86/kernel/sev-shared.c
@@ -125,10 +125,9 @@ static enum es_result verify_exception_info(struct ghcb *ghcb, struct es_em_ctxt
 	return ES_VMM_ERROR;
 }
 
-static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
-					  struct es_em_ctxt *ctxt,
-					  u64 exit_code, u64 exit_info_1,
-					  u64 exit_info_2)
+enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb, bool set_ghcb_msr,
+				   struct es_em_ctxt *ctxt, u64 exit_code,
+				   u64 exit_info_1, u64 exit_info_2)
 {
 	/* Fill in protocol and format specifiers */
 	ghcb->protocol_version = GHCB_PROTOCOL_MAX;
@@ -138,7 +137,14 @@ static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
 	ghcb_set_sw_exit_info_1(ghcb, exit_info_1);
 	ghcb_set_sw_exit_info_2(ghcb, exit_info_2);
 
-	sev_es_wr_ghcb_msr(__pa(ghcb));
+	/*
+	 * Hyper-V unenlightened guests use a paravisor for communicating and
+	 * GHCB pages are being allocated and set up by that paravisor. Linux
+	 * should not change the GHCB page's physical address.
+	 */
+	if (set_ghcb_msr)
+		sev_es_wr_ghcb_msr(__pa(ghcb));
+
 	VMGEXIT();
 
 	return verify_exception_info(ghcb, ctxt);
@@ -418,7 +424,7 @@ static enum es_result vc_handle_ioio(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
 		 */
 		sw_scratch = __pa(ghcb) + offsetof(struct ghcb, shared_buffer);
 		ghcb_set_sw_scratch(ghcb, sw_scratch);
-		ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO,
+		ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_IOIO,
 					  exit_info_1, exit_info_2);
 		if (ret != ES_OK)
 			return ret;
@@ -460,7 +466,8 @@ static enum es_result vc_handle_ioio(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
 
 		ghcb_set_rax(ghcb, rax);
 
-		ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO, exit_info_1, 0);
+		ret = sev_es_ghcb_hv_call(ghcb, true, ctxt,
+					  SVM_EXIT_IOIO, exit_info_1, 0);
 		if (ret != ES_OK)
 			return ret;
 
@@ -491,7 +498,7 @@ static enum es_result vc_handle_cpuid(struct ghcb *ghcb,
 		/* xgetbv will cause #GP - use reset value for xcr0 */
 		ghcb_set_xcr0(ghcb, 1);
 
-	ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_CPUID, 0, 0);
+	ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_CPUID, 0, 0);
 	if (ret != ES_OK)
 		return ret;
 
@@ -516,7 +523,7 @@ static enum es_result vc_handle_rdtsc(struct ghcb *ghcb,
 	bool rdtscp = (exit_code == SVM_EXIT_RDTSCP);
 	enum es_result ret;
 
-	ret = sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, 0, 0);
+	ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, exit_code, 0, 0);
 	if (ret != ES_OK)
 		return ret;
 
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index 2de1f36..113d3ae 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -648,7 +648,8 @@ static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
 		ghcb_set_rdx(ghcb, regs->dx);
 	}
 
-	ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_MSR, exit_info_1, 0);
+	ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_MSR,
+				  exit_info_1, 0);
 
 	if ((ret == ES_OK) && (!exit_info_1)) {
 		regs->ax = ghcb->save.rax;
@@ -867,7 +868,7 @@ static enum es_result vc_do_mmio(struct ghcb *ghcb, struct es_em_ctxt *ctxt,
 
 	ghcb_set_sw_scratch(ghcb, ghcb_pa + offsetof(struct ghcb, shared_buffer));
 
-	return sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, exit_info_1, exit_info_2);
+	return sev_es_ghcb_hv_call(ghcb, true, ctxt, exit_code, exit_info_1, exit_info_2);
 }
 
 static enum es_result vc_handle_mmio_twobyte_ops(struct ghcb *ghcb,
@@ -1117,7 +1118,7 @@ static enum es_result vc_handle_dr7_write(struct ghcb *ghcb,
 
 	/* Using a value of 0 for ExitInfo1 means RAX holds the value */
 	ghcb_set_rax(ghcb, val);
-	ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WRITE_DR7, 0, 0);
+	ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_WRITE_DR7, 0, 0);
 	if (ret != ES_OK)
 		return ret;
 
@@ -1147,7 +1148,7 @@ static enum es_result vc_handle_dr7_read(struct ghcb *ghcb,
 static enum es_result vc_handle_wbinvd(struct ghcb *ghcb,
 				       struct es_em_ctxt *ctxt)
 {
-	return sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WBINVD, 0, 0);
+	return sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_WBINVD, 0, 0);
 }
 
 static enum es_result vc_handle_rdpmc(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
@@ -1156,7 +1157,7 @@ static enum es_result vc_handle_rdpmc(struct ghcb *ghcb, struct es_em_ctxt *ctxt
 
 	ghcb_set_rcx(ghcb, ctxt->regs->cx);
 
-	ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_RDPMC, 0, 0);
+	ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_RDPMC, 0, 0);
 	if (ret != ES_OK)
 		return ret;
 
@@ -1197,7 +1198,7 @@ static enum es_result vc_handle_vmmcall(struct ghcb *ghcb,
 	if (x86_platform.hyper.sev_es_hcall_prepare)
 		x86_platform.hyper.sev_es_hcall_prepare(ghcb, ctxt->regs);
 
-	ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_VMMCALL, 0, 0);
+	ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_VMMCALL, 0, 0);
 	if (ret != ES_OK)
 		return ret;
 

  reply	other threads:[~2021-10-25 16:34 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-25 12:21 [PATCH V9 0/9] x86/Hyper-V: Add Hyper-V Isolation VM support(First part) Tianyu Lan
2021-10-25 12:21 ` [PATCH V9 1/9] x86/hyperv: Initialize GHCB page in Isolation VM Tianyu Lan
2021-10-25 12:21 ` [PATCH V9 2/9] x86/hyperv: Initialize shared memory boundary in the " Tianyu Lan
2021-10-25 12:21 ` [PATCH V9 3/9] x86/hyperv: Add new hvcall guest address host visibility support Tianyu Lan
2021-10-25 12:21 ` [PATCH V9 4/9] Drivers: hv: vmbus: Mark vmbus ring buffer visible to host in Isolation VM Tianyu Lan
2021-10-25 12:21 ` [PATCH V9 5/9] x86/sev-es: Expose sev_es_ghcb_hv_call() to call ghcb hv call out of sev code Tianyu Lan
2021-10-25 16:34   ` tip-bot2 for Tianyu Lan [this message]
2021-10-25 12:21 ` [PATCH V9 6/9] x86/hyperv: Add Write/Read MSR registers via ghcb page Tianyu Lan
2021-10-25 12:21 ` [PATCH V9 7/9] x86/hyperv: Add ghcb hvcall support for SNP VM Tianyu Lan
2021-10-25 12:21 ` [PATCH V9 8/9] Drivers: hv: vmbus: Add SNP support for VMbus channel initiate message Tianyu Lan
2021-10-25 12:21 ` [PATCH V9 9/9] Drivers: hv : vmbus: Initialize VMbus ring buffer for Isolation VM Tianyu Lan
2021-10-25 20:55 ` [PATCH V9 0/9] x86/Hyper-V: Add Hyper-V Isolation VM support(First part) Wei Liu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=163517966616.626.15035578353013624242.tip-bot2@tip-bot2 \
    --to=tip-bot2@linutronix.de \
    --cc=Tianyu.Lan@microsoft.com \
    --cc=bp@suse.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-tip-commits@vger.kernel.org \
    --cc=mikelley@microsoft.com \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.